Carbon Nanotube in Cement Manufacturing

 Carbon Nanotube in Cement Manufacturing

Carbon nanotubes (CNTs) are cylindrical structures made up of carbon atoms arranged in a unique tubular shape. They possess extraordinary mechanical, electrical, and thermal properties, making them highly versatile and valuable in various fields of science and technology.

Carbon nanotubes can be categorized into two main types: Single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). SWNTs consist of a single cylindrical layer of carbon atoms, while MWNTs comprise multiple concentric layers of carbon sheets.

The most common method for synthesizing carbon nanotubes is through a process called chemical vapor deposition (CVD). In CVD, a carbon-containing gas, such as methane (CH4), is introduced into a reactor chamber containing a substrate or catalyst, typically made of a transition metal like iron, nickel, or cobalt. The process involves the following steps:

1.     Substrate preparation: The catalyst material is prepared by depositing a thin layer onto a substrate, such as a silicon wafer.

2.     Reactor chamber setup: The substrate with the catalyst is placed inside a reactor chamber, which is then sealed and evacuated to remove any impurities.

3.     Heating and carbon feedstock introduction: The reactor chamber is heated to a specific temperature, typically in the range of 600 to 1000 degrees Celsius. The carbon-containing gas, such as methane, is introduced into the chamber.

4.     Nanotube growth: The carbon atoms from the gas decompose in the presence of the catalyst, and the carbon nanotubes begin to grow on the surface of the catalyst. The process is driven by the catalytic reaction and the diffusion of carbon atoms.

5.     Cooling and collection: Once the desired growth time has elapsed, the reactor chamber is cooled down, and the carbon nanotubes are collected from the catalyst-coated substrate.

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Other methods, 

Carbon nanotubes can be synthesized using several methods, including:

1.     Arc Discharge: In this method, a high-voltage electric arc is created between two graphite electrodes in an inert gas atmosphere. The intense heat generated vaporizes the graphite, and as the vapor cools down, carbon nanotubes form. The resulting mixture contains a combination of SWCNTs and MWCNTs.

2.     Laser Ablation: In laser ablation, a high-powered laser is focused on a carbon target in the presence of a reactive gas. The laser vaporizes the carbon, and the resulting plume contains carbon nanotubes. This method usually yields a higher proportion of SWCNTs.

3.     Chemical Vapor Deposition (CVD): CVD is a widely used method for growing carbon nanotubes. It involves the decomposition of hydrocarbon gases, such as methane, over a catalyst substrate, typically a transition metal like iron, cobalt, or nickel. The hydrocarbon gases are introduced into a reaction chamber, and under specific temperature and pressure conditions, carbon atoms deposit onto the catalyst surface and form nanotubes. The catalyst promotes the growth of nanotubes, which can be either SWCNTs or MWCNTs depending on the reaction conditions.

4.     High-Pressure Carbon Monoxide (HiPCO) Method: HiPCO is a variant of the CVD method where carbon monoxide gas is used as the carbon source instead of hydrocarbons. The carbon monoxide reacts with iron nanoparticles as the catalyst to produce carbon nanotubes.

After synthesis, carbon nanotubes need to be purified and separated from the byproducts and catalyst particles. Techniques such as filtration, centrifugation, and chemical treatments are employed to purify and obtain the desired type of nanotubes.

 

Carbon nanotubes have tremendous potential in a wide range of applications, including electronics, energy storage, composites, sensors, and biomedical devices, due to their exceptional strength, high electrical and thermal conductivity, and unique structural properties.

Carbon Nanotubes in Cement Manufacturing:

Carbon nanotubes (CNTs) have shown promise in Cement manufacturing due to their unique properties and potential benefits. Here's an overview of why and how CNTs can be used in cement, along with their advantages, disadvantages, and cost considerations:

Advantages:

1.     Improved Mechanical Properties: CNTs can enhance the mechanical properties of cement composites. When added in small percentages, CNTs act as reinforcement, increasing the strength, toughness, and durability of the cement matrix. This can result in improved resistance to cracking, higher flexural and compressive strength, and better overall mechanical performance.

 

2.     Enhanced Electrical and Thermal Conductivity: The high electrical and thermal conductivity of CNTs can be harnessed in cement composites. By incorporating CNTs, cement can acquire electrical conductivity, allowing for applications like self-monitoring, sensing structural changes, or electromagnetic shielding. Additionally, the high thermal conductivity of CNTs can enhance the heat transfer properties of cement composites, making them useful for applications requiring heat dissipation or thermal management.

 

3.     Reduced Cracking and Shrinkage: Cement composites containing CNTs have shown potential in reducing cracking and shrinkage. CNTs can act as nucleation sites for calcium hydroxide crystals, promoting densification and reducing the formation of microcracks. This can enhance the long-term durability and performance of the cementitious material.

 

4.     Environmental Benefits: Cement production is a significant contributor to greenhouse gas emissions. By incorporating CNTs, which have a low carbon footprint due to their high carbon content, the overall environmental impact of cement manufacturing can be reduced. The use of CNTs can contribute to sustainability efforts and mitigate the environmental footprint of the cement industry.

 

5.     Tailored Functionality: CNTs offer the potential for tailored functionality in cement composites. Their unique properties, such as electrical conductivity, can be leveraged to develop smart cement composites capable of self-sensing, self-healing, or other advanced functionalities. This opens up opportunities for innovative applications and the integration of cement-based materials with emerging technologies.

6.     Their high surface area is beneficial for cement manufacturing, adding just 1g of MW-CNTs to 1kg of cement doubles the available surface area for CSH dentrite formation in the initial stages of cement setting. This aids greatly in early strength development. In tests conducted at the University of Texas Arlington Center for Advanced Construction Materials, the addition of 0.1% of CHASM Advanced Materials' NTeC™-C 'hybrid' MW-CNT led to 41% higher 3 day strength in a laboratory testing. 28 day strength also rose by around 20%. The high aspect ratio also caused stiffness, as defined by the Young's Modulus, to rise by 86%, while flexural strength doubled.
While these figures reduce somewhat when we translate from the laboratory to the real world, the use of MW-CNTs means that we can get a bigger 'bang for our buck' from the same amount of clinker. We can add more supplementary cementitious materials (SCMs), some of which lead to lower early strength, and still achieve the same performance. Higher flexural strength would allow for reductions in the thickness of concrete road surfaces and higher tensile strength will permit the use of less steel in high-rise buildings. All of these contribute to a massive potential to reduce the mass of cement - and thus clinker and CO2 - used in construction. We estimate that in our home market of the US, we could reduce the amount of CO2 produced by the cement sector by 30Mt/yr, just by dosing MW-CNTs at 0.1% by weight.
MW-CNTs may also present 'smart concrete' applications. For example, CHASM Advanced Materials is also looking at how the conductive properties of CNTs might be harnessed to measure stress in structures like bridges, as well as to assess building safe.

 7.     Reduced Carbon Footprint: Cement production is a significant contributor to greenhouse gas emissions. By incorporating CNTs, which have a low carbon footprint due to their high carbon content, it's possible to reduce the overall environmental impact of cement manufacturing.

Disadvantages and Challenges

 a. Cost: Carbon nanotubes are relatively expensive to produce, which can affect the cost-effectiveness of their use in large-scale cement manufacturing. However, as production methods advance and economies of scale are realized, the costs may decrease over time.

 b. Dispersion and Agglomeration: Proper dispersion of CNTs in cement composites is crucial to achieve their desired properties. However, CNTs have a tendency to agglomerate, forming clumps that can hinder uniform distribution and affect the performance of the composite.

 c. Compatibility: Ensuring compatibility between CNTs and the cement matrix is essential. CNTs need to be functionalized or modified to improve their interaction with cementitious materials and prevent adverse reactions that could compromise the composite's properties.

 d. Health and Safety Concerns: The potential health and safety risks associated with the handling and exposure to CNTs during manufacturing and construction need to be carefully considered and addressed to ensure the well-being of workers and the environment.

 Cost Considerations:

 The cost of incorporating CNTs into cement manufacturing depends on various factors, including the type of CNTs used, their quality, production scale, and the specific application requirements. Currently, the cost of CNTs remains relatively high compared to conventional materials, which may limit their widespread adoption in the cement industry. However, ongoing research and advancements in production techniques could lead to cost reductions in the future.

It's worth noting that the use of carbon nanotubes in cement manufacturing is still a developing area of research and application. While there is significant potential, further studies and technological advancements are needed to overcome challenges and fully exploit the benefits of CNTs in cement composites.

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Welding Electrode E6013 Vs Welding Electrode E7018

Welding Electrode E-6013

The number "6013" in the welding electrode designation E6013 refers to the classification system used for identifying different types of welding electrodes. The American Welding Society (AWS) uses a four or five-digit numbering system to classify electrodes based on their characteristics, intended use, and composition.

In the case of E6013, let's break down the numbers:

1. "E": The "E" in the electrode classification stands for "Electrode." It signifies that the designation is for a consumable welding electrode.

2. "60": The first two digits, "60," represent the minimum tensile strength of the deposited weld metal measured in kilopounds per square inch (ksi). In this case, "60" indicates that the electrode can produce a weld with a minimum tensile strength of approximately 60 ksi (413 MPa).

3. "1": The third digit signifies the welding position capabilities of the electrode. In the case of "1," it means that the E6013 electrode can be used in all positions, including flat, horizontal, vertical, and overhead.

4. "3": The fourth digit represents the type of coating and the welding current. The specific meaning of "3" in E6013 can vary depending on the classification system used. In the AWS system, "3" typically indicates that the electrode has a high cellulose sodium coating and can be used with both AC (alternating current) and DC (direct current) welding machines.

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Welding Electrode E-7018

The number "7018" in the welding electrode designation E7018 refers to the classification system used for identifying different types of welding electrodes. The American Welding Society (AWS) uses a four or five-digit numbering system to classify electrodes based on their characteristics, intended use, and composition.

Let's break down the numbers in E7018:

1. "E": The "E" in the electrode classification stands for "Electrode." It signifies that the designation is for a consumable welding electrode.

2. "70": The first two digits, "70," represent the minimum tensile strength of the deposited weld metal measured in kilopounds per square inch (ksi). In this case, "70" indicates that the electrode can produce a weld with a minimum tensile strength of approximately 70 ksi (483 MPa).

3. "1": The third digit signifies the welding position capabilities of the electrode. In the case of "1," it means that the E7018 electrode can be used in all positions, including flat, horizontal, vertical, and overhead.

4. "8": The fourth digit represents the type of coating and the welding current. In the AWS system, the specific meaning of "8" in E7018 indicates that the electrode has a low hydrogen potassium iron powder coating and is designed for use with DC (direct current) welding machines.

When comparing low hydrogen potassium iron powder coating and high cellulose sodium coating, there are several factors to consider, including their properties, applications, and potential advantages or disadvantages. However, it's important to note that specific details about these coatings, such as their availability or recent developments, might not be included in my training data, which goes up until September 2021. Therefore, I'll provide a general overview based on the information available up until that point.

1. Low Hydrogen Potassium Iron Powder Coating:

   • Low hydrogen potassium iron powder coatings are typically used in welding applications.
   • They are designed to minimize the presence of hydrogen in the weld and reduce the risk of hydrogen-induced cracking.
   • These coatings often contain potassium compounds to help mitigate hydrogen-related issues.
   • They are commonly used for welding high-strength steels and critical applications where weld integrity is crucial.
   • The low hydrogen characteristic of this coating makes it suitable for welding structures subjected to high stress or pressure.

2. High Cellulose Sodium Coating:

   • High cellulose sodium coatings, also known as cellulosic electrodes, are used in shielded metal arc welding (SMAW) processes.
   • Cellulosic coatings contain a high percentage of cellulose material, such as wood pulp or cotton, mixed with sodium compounds.
   • These coatings create a reducing environment during welding, which promotes deep penetration and faster welding speeds.
   • High cellulose sodium coatings are commonly used for welding pipes, especially in the oil and gas industry.
   • They provide good control over the shape and characteristics of the weld bead.

Comparing the two coatings, they serve different purposes and have distinct characteristics:

• Application: Low hydrogen potassium iron powder coatings are primarily used in welding high-strength steels and critical applications, while high cellulose sodium coatings are commonly employed in pipe welding, especially in the oil and gas industry.
• Hydrogen Control: Low hydrogen potassium iron powder coatings are specifically formulated to minimize hydrogen-induced cracking, whereas high cellulose sodium coatings do not have the same focus on hydrogen control.
• Welding Speed: High cellulose sodium coatings often allow for faster welding speeds due to the reducing environment they create during welding.
• Penetration: High cellulose sodium coatings generally provide deep penetration, which can be advantageous in certain applications.
• Weld Bead Control: Cellulosic coatings, such as high cellulose sodium coatings, can offer good control over the shape and characteristics of the weld bead.

    following is comparison between 6013 and 7018 welding electrode in tabular form.

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Factor to be noted: When Project Manager became the President or Unit Head of cement plant operation

When Project Manager became the President or Unit Head of cement plant operation 

When a project manager becomes a unit head of a cement plant and approaches the management of the plant like project management, there can be both positive and negative outcomes for the company.

Positive outcomes:

1. Improved Efficiency: Project managers are skilled at optimizing processes and resources, which can lead to greater efficiency in plant operations. By using project management techniques to manage plant operations, the unit head can identify and address bottlenecks, streamline workflows, and eliminate waste.

2. Stronger Focus on Results: Project management is focused on delivering results, which can be beneficial in a plant setting where performance is measured in terms of production output, quality, and safety. By applying project management principles, the unit head can create a culture of accountability and ensure that the plant is meeting its targets.

3. Better Risk Management: Project managers are trained to identify and manage risks, which is a critical skill in a hazardous industry like cement manufacturing. By applying risk management principles, the unit head can identify potential safety hazards and take proactive measures to prevent accidents.

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Negative outcomes:

If a project manager becomes the unit head of a cement plant and works in a way that is focused solely on project management, it may lead to some potential losses for the company. Here are some possible scenarios:

1. Lack of Focus on Plant Operations: As a project manager, the focus of the individual is typically on the project and its successful completion. However, as a unit head of a cement plant, their responsibilities extend beyond the project to the overall operations of the plant. If the individual does not shift their focus to plant operations, it could lead to operational issues and delays, which may ultimately impact the company's revenue and profits.

2. Poor Resource Allocation: Project managers are trained to manage resources efficiently and effectively to deliver projects on time and within budget. However, the resources required for plant operations are different from those required for a project. If the individual does not allocate resources appropriately, it may lead to wastage of resources, higher operating costs, and reduced profitability for the company.

3. Inadequate Knowledge of Cement Plant Operations: While a project manager may have experience in managing projects, they may not necessarily have the requisite knowledge of cement plant operations. This lack of knowledge could lead to poor decision-making, operational inefficiencies, and safety issues.

4. Over-Reliance on Process: Project managers may be too focused on following established processes and procedures, which may not always be appropriate in a dynamic manufacturing environment. This can stifle innovation and creativity in plant operations.

5. Failure to Manage Stakeholders: As a unit head of a cement plant, the individual will have to manage a variety of stakeholders, including employees, customers, suppliers, and regulatory bodies. If the individual is solely focused on project management, they may not give enough attention to stakeholder management, leading to strained relationships and potential legal issues.

There can be several reasons why a candidate with project management experience may struggle to operate a cement plant and manage the team effectively:

1. Lack of Operational Knowledge: While project management skills can be valuable in many industries, they may not be sufficient to effectively manage a cement plant. Cement manufacturing is a highly specialized field that requires a deep understanding of the production process, safety requirements, environmental regulations, and other operational considerations. A project manager who lacks this operational knowledge may struggle to make informed decisions and manage the team effectively.

2. Inadequate Training and Support: Even if a candidate has the right technical knowledge, they may struggle if they do not receive adequate training and support. Managing a cement plant requires a range of skills, including team management, problem-solving, and strategic planning. A candidate with project management experience may need additional training and coaching to develop these skills.

3. Poor Communication and Collaboration: A project manager who is used to working independently or with a small project team may struggle to communicate effectively and collaborate with a larger team of operational managers and employees. Cement plant operations require a high degree of coordination and collaboration across different departments and functions, and a candidate who fails to involve all stakeholders may struggle to achieve their goals.

4. Resistance to Change: A candidate who is used to working in a project-based environment may struggle to adapt to the slower pace and longer timelines of cement plant operations. They may also struggle to work within the existing organizational culture and may be resistant to changing established practices and procedures.

5. Lack of Focus on Employee Development: A project manager who is focused solely on achieving project goals may neglect the personal and professional development of their team members. This can lead to low morale, high turnover, and reduced productivity. A candidate with project management experience may need to shift their focus to developing the skills and capabilities of their team members to achieve long-term success.

        Overall, managing a cement plant requires a unique set of skills and knowledge that may not be fully developed in a candidate with project management experience. To succeed in this role, the candidate may need to receive additional training and support, adapt their communication and collaboration style, and focus on developing the skills of their team members.        

        Overall, if a project manager becomes a unit head of a cement plant and does not adapt to the new role and responsibilities, it could lead to various losses for the company, including reduced profitability, operational inefficiencies, safety issues, and legal challenges.

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comparison of splice joint vs butt welding joint

Comparison of splice joint vs butt welding joint

To compare the strength of a web and flange splice connection versus a full-penetration butt weld joint for an ISMB 200 section according to Indian Standard, we need to consider the design parameters specified in the IS 800: 2007 code.

For the web and flange splice connection, we can assume a splice plate thickness of t = 12 mm, with the splice plate extending to 150 mm beyond the splice location in both directions. The length of the splice plate can be assumed to be 2.5 times the depth of the section (i.e., 500 mm).

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For the full-penetration butt weld joint, we can assume a butt weld length of 150 mm on each side of the joint, and a throat thickness of 8 mm.

Based on these assumptions, we can calculate the strength of each type of joint using the following formula:

Strength of joint = Design strength x Length of joint

where the design strength is calculated as per the IS 800: 2007 code.

For the web and flange splice connection, the design strength can be calculated as follows:

Design strength = 0.9 x fy x t x (150 + 500) / 1000

where fy is the yield strength of the steel, which can be assumed to be 250 MPa.

Plugging in the values, we get:

Design strength = 0.9 x 250 x 12 x 650 / 1000 = 1755 kN

Assuming the length of the splice plate to be 2.5 times the depth of the section, the total length of the splice joint would be:

Length of joint = 2.5 x 200 = 500 mm

Therefore, the strength of the web and flange splice joint would be:

Strength of joint = 1755 kN x 500 mm = 878 kNm

For the full-penetration butt weld joint, the design strength can be calculated as follows:

Design strength = 0.7 x fu x 8 x 150 / 1000

where fu is the ultimate tensile strength of the steel, which can be assumed to be 410 MPa.

Plugging in the values, we get:

Design strength = 0.7 x 410 x 8 x 150 / 1000 = 344 kN

Assuming the length of the butt weld to be 150 mm on each side, the total length of the joint would be:

Length of joint = 2 x 150 = 300 mm

Therefore, the strength of the full-penetration butt weld joint would be:

Strength of joint = 344 kN x 300 mm = 103.2 kNm

As we can see, the web and flange splice joint is significantly stronger than the full-penetration butt weld joint for the given section and design parameters. However, it is important to note that the choice of joint type will depend on several factors such as cost, ease of fabrication and installation, and the specific requirements of the project.

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Full penetrate butt welding strength calculation with example

Full penetrate butt welding strength calculation with example

First, let's explain what full penetration welding joint is. It is a type of welding joint where the weld metal completely penetrates the thickness of the joint, resulting in a very strong bond between the two pieces being welded. This type of joint is commonly used in high-stress applications where strength is crucial.

To calculate the share strength of a full penetration welding joint, you would need to determine the area of the weld and the shear strength of the material being welded. The formula for shear strength is:

Shear strength = 0.6 x tensile strength

Assuming we have a full penetration welding joint with a steel plate of 10 mm thickness and a weld of 10 mm width, we can calculate the area of the weld as follows:

Area of weld = thickness of plate x width of weld Area of weld = 10 mm x 10 mm Area of weld = 100 mm²

Next, we need to determine the shear strength of the steel being welded. Assuming the steel has a tensile strength of 500 MPa, we can calculate the shear strength as follows:

Shear strength = 0.6 x tensile strength Shear strength = 0.6 x 500 MPa Shear strength = 300 MPa

Finally, we can calculate the share strength of the full penetration welding joint as follows:

Shear strength of weld = shear strength x area of weld Shear strength of weld = 300 MPa x 100 mm² Shear strength of weld = 30,000 N

To calculate the tensile strength of the full penetration welding joint, we would need to determine the cross-sectional area of the joint and the tensile strength of the material being welded. The formula for cross-sectional area is:

Cross-sectional area = thickness of plate x width of joint

Assuming we have the same steel plate and weld as before, we can calculate the cross-sectional area of the joint as follows:

Cross-sectional area = thickness of plate x width of joint Cross-sectional area = 10 mm x 10 mm Cross-sectional area = 100 mm²

Next, we need to determine the tensile strength of the steel being welded. Assuming the steel has a tensile strength of 500 MPa, we can use this value directly.

Finally, we can calculate the tensile strength of the full penetration welding joint as follows:

Tensile strength of weld = tensile strength x cross-sectional area Tensile strength of weld = 500 MPa x 100 mm² Tensile strength of weld = 50,000 N

Following point should be noted before calculation:

Full penetration welding joint refers to a type of welding joint where the weld metal extends completely through the thickness of the joint. The strength of a full penetration welding joint can be calculated using the ultimate tensile strength of the base metal and the strength of the weld metal.

The strength of the weld metal can be calculated based on the type of welding process used and the welding consumables used. For example, for a Shielded Metal Arc Welding (SMAW) process using an E7018 electrode, the tensile strength of the weld metal can be assumed to be around 70,000 psi (480 MPa).

The strength of the base metal can be determined from material testing or from the relevant material standards, such as ASTM or ISO standards.

To calculate the total strength of the full penetration welding joint, the minimum of the tensile strength of the base metal and the weld metal should be considered. This is because the strength of the joint is limited by the weaker of the two materials.

The calculation of the tensile strength of a full penetration welding joint can be done using the following formula:

Tensile strength of joint = Minimum (Tensile strength of base metal, Tensile strength of weld metal)

Here is an example calculation of the tensile strength of a full penetration welding joint:

Assume that a full penetration welding joint is made using SMAW process with an E7018 electrode. The base metal is ASTM A36 steel with a minimum tensile strength of 58,000 psi (400 MPa). The weld metal has a tensile strength of 70,000 psi (480 MPa).

Using the formula above, the tensile strength of the joint can be calculated as:

Tensile strength of joint = Minimum (58,000 psi, 70,000 psi) = 58,000 psi

Therefore, the tensile strength of the full penetration welding joint in this example is 58,000 psi.

The code reference for full penetration welding joint strength calculation can be found in various welding codes such as AWS D1.1 (Structural Welding Code - Steel) and ASME Boiler and Pressure Vessel Code Section IX.

Full Penetration Welding Joint Strength Calculation

A full penetration welding joint is a type of joint that results in a very strong bond between two pieces being welded. Here's how to calculate the share strength and tensile strength of such a joint:

Share Strength Calculation

To calculate the share strength of a full penetration welding joint, you need to determine the area of the weld and the shear strength of the material being welded. Here's the formula:

Shear strength = 0.6

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Comparison between welding electrode 6013 and 7018

Comparison Between Welding Electrode 6013 and 7018:

Welding electrodes are metal wires with a flux coating that melt and fuse two pieces of metal together. Two common types of welding electrodes are the 6013 and 7018. The 6013 electrode is a general-purpose welding electrode used for welding mild steel, galvanized steel, and some low alloy steels. The 7018 electrode is a low hydrogen welding electrode used for welding high-strength, low-alloy steels, carbon steels, and some low alloy steels in high-stress environments such as pressure vessels, pipelines, and structural steel fabrication.

The 6013 electrode has a high cellulose potassium coating with iron powder in the coating. It can be used with either alternating current (AC) or direct current positive (DC+) power sources. The 7018 electrode has a low hydrogen potassium coating with iron powder and other elements such as nickel and molybdenum in the coating. It is also used with AC or DC+ power sources.

Before welding with either electrode, the surface must be cleaned and free of any contaminants, such as rust or oil. However, the 7018 electrode requires preheating for thick materials, and a low hydrogen rod oven should be used to prevent moisture absorption into the coating.

Tabular Comparison Between Welding Electrode 6013 and 7018:

Welding Electrode	6013	7018
Welding Position	All Positions	Flat, Horizontal, Vertical, Overhead
Current Type	AC or DC+	AC or DC+
Diameter Sizes	1/16 to 5/32 inches	3/32 to 1/4 inches
Tensile Strength	60,000 psi	70,000 psi
Typical Applications	General purpose welding, sheet metal work, maintenance and repair	Heavy-duty welding, structural steel fabrication, pressure vessels, pipelines
Material Composition	High cellulose potassium-coated electrode with iron powder in the coating.	Low hydrogen potassium-coated electrode with iron powder and other elements such as nickel and molybdenum in the coating.
Suitable For	General purpose welding of mild steel, galvanized iron, and some low alloy steels.	Heavy-duty welding of high-strength, low-alloy steels, carbon steels, and some low alloy steels. Suitable for use in high-stress environments such as pressure vessels, pipelines, and structural steel fabrication.
Preparation Before Welding	Surface must be cleaned and free of any contaminants, such as rust or oil. No preheating is required.	Surface must be cleaned and free of any contaminants, such as rust or oil. Preheating is recommended for thick materials, and a low hydrogen rod oven should be used to prevent moisture absorption into the coating.

You may contact us for fabrication related drawing and detailing as per below 

email: playingcad@gmail.com

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Dalmia Bharat group Acuired Jaypee Group's Cement Asset for 5666 Crore indian rupees.

 Dalmia Bharat group Acuired Jaypee Group's Cement Asset for 5666 Crore indian rupees.

Jaypee group on monday, 12th Dec, 2022, announced that the bidding agreement had been signed for selling of Cement group to Dalmia Bharat group @ 5666 crore, enterprise value.

​The divestment includes cement plants with an aggregate capacity of 9.4 million tonne of cement, clinker capacity of 6.7 million tonne, and 280 MW capacity thermal power plant located at Nigri, Madhya Pradesh.

following plants will be aquired by Dalmia Bharat group in this deal

"These assets are situated in the states of Madhya Pradesh, Uttar Pradesh and Chhattisgarh," said Dalmia Bharat.

1. Jaypee Rewa (MP) - 1.7 MTPA

2. Chunar Cement factory, Churk (UP) - 2.5 MTPA

3. Jaypee Nigri Cement Nigri (M.P.)- 2 MTPA

4. Churk - 1 MTPA

5. Bhilai Jaypee Cement, Chattishgadh - 2.2 MTPA

Total Capacity: 9.4 MTPA

The move would help Dalmia Bharat Ltd increase its manufacturing capacity to 45.3 million tonnes per annum (MTPA) from the existing 35.9 MTPA.

This deal represent a significant step towards realisation of its vision to emerge as a pan-India cement company with a capacity of 75 MnT by FY27 and 110-130 MnT by FY31 by Dalmia Bharat group.

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Top Bidders

1. Dalmia Bharat: 5666 Crore

2. Adani: 5000 Crore

3. Ultra Tech: Interest shown but not done due to Over valuation of assets.

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Consumption of Electric Power & Thermal Energy in Cement Industry (Benchmarks -2021)

Introduction:

Cement production contributes around 8% of the anthropogenic CO2 (carbon dioxide) emissions globally.

China is the largest cement producer, accounting for about 55% of global production. India is the world’s second-largest cement producer and consumer, accounting for over eight per cent of the global installed capacity which is only expected to grow.

The cement industry is one of the world’s most energy intensive industries. The sector contributes about 8% of the global anthropogenic CO₂ emission, and about 60-62% of the greenhouse gas (GHG) emissions are attributed to ‘process emission’ that happens during clinker manufacturing.

Today’s need to study the scope of improvements in cement manufacturing process & technology, The market offers a wide variety of alternative solutions; besides, this note provides reviews of opportunities to improve energy efficiency in a cement plant. However, the technology is constantly developing, so the available alternatives may change in a upcoming years.

Power Consumption of Cement Manufacturing Units/Plants

The cement industry is high-power consumption industry, power consumption in the cement grinding process (only grinding excluding clinkerisation) takes a large percentage in the whole production, electric power consumption is about 50%-70% of the total power consumption.

With more and more strict Energy conservation and environmental protection policy published by govt., excess production capacity, and higher market competition, energy conservation in cement grinding plant is the main key for Cement Manufacturing to achieve the purpose of reducing power consumption. Fuel and electricity are the largest variable cost of production at cement plants. Variable costs are typically about 50% of overall operating costs, so energy cost is usually the single largest production cost, besides raw materials. Labor cost is relatively a small part in the Cement Manufacturing Plants.

Most of the energy is used in drives of the equipment, a lot of power is consumed in the processes of Raw material crushing, burning of raw material to make clinker, materials transport, cement grinding & cement transport. The cement industry thermal energy (natural gas consumption) is used in the process of heating of the raw meal (about 90% of total gas consumption), which involves clinker production in large kilns. In the most cases natural gas is used as a fuel in place of coal, Easier delivery, heat control are the main advantages of natural gas, there are other fuels can be used in cement rotary kiln, such as biofuels, the only problem is that it might cause pollution with unwanted gas created, or it is not sustainable for a continuous production.

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At present scenario, the cement grinding system, the major cement grinding equipment includes loop flow ball mill, roller press, ball mill semi-finishing system, and vertical mill system (VRM), in which ball mill and vertical mill are 2 main cement grinding systems in Cement Manufacturing, however all kinds of cement grinding plants have their own advantages and disadvantages, The innovation and technological upgradation in progress are constantly happening year to year, and the cement grinding technology is also developing towards high efficiency and intelligence and moving to artificial intelligence system.

Some highlights of Cement Manufacturing Units/Plants (in Indian perspective

 Approximate power consuption in cement plant (as per benchmark,CII-2021)

Cost of Production per Ton of cement:

Average electricity consumption for Production of per ton of cement:

 

Improvement in usage of green power for production of cement:

 

Targets to reduce the emission of CO₂ in cement production:

 

Power Consumption of Cement Manufacturing Plant at Present

At present, the average level of unit energy consumption of Cement Manufacturing Plants (cement grinding only, except clinkerisation) is at 33 kWh, in some Cement Manufacturing Plants, it could be 40 kWh that is  higher than the average number, due to technology improvement, upgradation of equipment, and new type abrasion materials, the Cement Manufacturing Plant could reduce the unit energy consumption of the grinding process to 18.8 kWh per ton of cement. For example, the power consumption of “Dalmia Cement – Ariyalur” grinding has been reduced to 22.3 kwh per ton, which is big progress has been made. It could save almost 1/3 of the average electricity consumption.

Power Consuption For Cement grinding (Benchmark, CII-India 2021):

·         Grinding Power: 18.8 kwh/hr (for PPC)

·         Packing Power :0.65 kwh/hr,

·         Emission of CO₂: 468 Kg/MT of Cement

 For complete cement plant:

·         Specific power consumption per ton of cement: International & national benchmark (56.14 kwh/ton, 56.00 kwh/ton)

·         Thermal power consumption per ton of cement: International & national benchmark (660 kcal/kg, 676 kcal/kg of clinker), (Best in india - Kotputli Cement Works Unit of ultra tech- 677 kcal/kg of clinker.)

Upto clinkerisation:

·         Specific electrical energy consuptin upto clinkerisation: International & national benchmark (42 kwh/ton, 42.5 kwh/ton)

The followings benchmarks have been set by CII, India for Cement Manufacturing plant and every plant of india is trying to achieve the same step by step.

 

There are so may researcher groups are working on different cement grinding methods and processes, it has made in-depth research and comparison on technical requirements. It is said that the semi-final grinding process can effectively solve the problem of the current combined grinding phenomenon, and further improve grinding efficiency by using a roller press system with ball mill grinding with high efficiency.

 

 

Thermal Energy Consumption in Cement Plant at A Glance:

The production process in cement plants is typically energy-intensive and it requires a large amount of resources. A typical well-equipped plant consumes about 3-4 GJ of energy to produce one ton of cement, the benchmark has been set in India by CII (FY2021) is 476 kcal/kg of cement ie 2.83 GJ of energy.

 

Improvement in Cement Grinding Process for productive cement quality:

1. Control of the proportion of finished products produced by the roller press system is the most appropriate. The specific surface area is more than the average, the residual sieve residue of 45um is nil. The cement capacity performance is the best at this time.
2. Control mining powder quality, blending raw materials, types and ratio.  
3. It is suggested that the cement production line includes the compatibility test of cement and concrete superplasticizer, and compare the correlation between cement composition, ratio table, particle distribution and cement performance.
4. Usage of artificial intelligence in cement grinding process is very beneficial to reduce the electric power consumption and higher quality of cement.
5. Some researchers’ studies suggest that capturing the carbon dioxide emissions before it enters to the atmosphere and storing it away through reverse calcination is the most effective method to de-carbonise the cement industry, reverse calcination could sequester up to 5% of cement’s emissions at present, it could be extended to 30% with the upgradation & improvement in technology. This process can be further enhanced by employing green energy instead of conventional fossil fuels to perform the process of calcination, noted the RBI.
6. Cement Ball Mill Control System will help to increase the productivity

a.    Control the fineness of raw material. The fineness of feed material is 48% ~ 52%, and that of outlet material is 32% ~ 35%.

b.    Flowing Rate Control. The flow rate of materials in the ball mill controlled, & the partition in the ball mill is forced to pass through the compartment; the discharge grate plate ventilation area is adjusted to select the use proper scheme, and the hollow part of the activation ring is blocked to adjust the material flow rate.

c.    Semi-final grinding needs very fine management to achieve the best results, from the host selection, admixture, clinker, parameter determination, adjustment, control tools, and other continuous research and performance-based adjustment.

 

Commitment of Various Cement plants in India

·    Mahendra Singhi, who is the managing director and chief executive officer of Dalmia Cement (Bharat) and the former president of the Cement Manufacturers Association, emphasised that the Indian cement sector is “the most energy and carbon-efficient globally” (when compared to cement sectors in other countries) and has the “lowest carbon footprints on account of early and voluntary actions from within the sector.”

“Despite price sensitivity, we are the lowest carbon footprints producer globally. In my view, it is the only way forward. Our early actions have made the sector ready for bigger and deeper changes,” he said.

Asked if a government regulation will push the cement industry to take giant strides on the issue, Singhi emphasised that the “regulations on energy and sustainability are already advancing.”

“For example, SEBI has introduced the BRSR (Business Responsibility and Sustainability Reporting) disclosures for top-1,000 companies in India. At the same time, regulations may not be needed in a system where the industry itself is proactive and taking self-motivated actions and targets,” he said.

Talking about his own company, Singhi said they are committed to becoming net-zero. “Dalmia Cement was the first cement group to commit to becoming carbon negative on account of a circular economy, energy efficiency, non-fossil power generation, electric mobility, use of green hydrogen, sustainable biomass use as a fuel and carbon capture and utilisation,” he said while adding that they demonstrated that decarbonisation of the industry makes business sense. In 2018, Dalmia cement announced the target of becoming carbon negative by 2040.

·         In 2021, another major cement player in India, ACC Limited, announced 2030 carbon emission reduction targets committing to reduce its CO2 intensity in cement operations from “511 kg in 2018 to 409 kg CO2 per ton of cementitious material by 2030.” It signed the “Business Ambition for 1.5°C pledge and joined the Race to Zero campaign of the United Nations Framework Convention on Climate Change.”

 

·         According to the RBI, India’s domestic cement industry has made “remarkable progress in reducing CO2 emission levels by about 36 per cent from 1.12t/t to 0.719t/t of cement produced between 1996 and 2017.” To further reduce it by half and “achieve the target of 0.35t CO2/t of cement by 2050, the cement industry requires an investment of $29 billion to $50 billion,” it notes.

 

References:

1.      https://qz.com/

2.      https://www.statista.com

3.      Systematicx institutional research

4.      CII, India

Tags: Consumption of electric energy in cement production, cost per ton of cement production, CO2 Emmission in cement plant, cement manufacturing process, thermal energy consuption in cement manufacturing process, cement plant, energy saving technics in cement manufacturing.

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