Refractory Installation Procedure and Heating Schedule to be followed after starting an Induction Furnace | Furnace Operation

Installation of refractories in any furnace is a tricky process and after the lining is done the most important thing is the heating schedule. That means how the furnace after repairing or with new refractory lining should be started, what should be the rate of heating (rising temperature) and holding time at any particular temperature. You cannot start the furnace by raising its temperature to peak at one go, as otherwise the refractories will be damaged or even the refractory lining may fall apart. The furnace starting heating schedule depends on various aspects including, thermal conductivity of the refractories used.

Here is a step-by-step guide for installation of Refractories (Ramming Masses, etc.) in Induction Furnace also the heating schedule that should be followed after starting the furnace:

 Read: 

• Refractories with their Specifications for Lining for different types of Induction Furnaces
• Refractory Lining Installation of Pipes and Chutes in a Furnace

1. Scrub all loose materials and clean the furnace.

2. Before using heat the refractory material (Ramming mass) at about 100^OC to make it free from moisture. Spread the material at the furnace bottom to about 50 - 60 mm thick layer at each time. Then ram the layer uniformly using a suitable rammer. The material has to be rammed layer by layer to get maximum compaction. Before ramming, little bit poking with a rod help to drive away the air-pockets trapped within the loose refractory material spread.

3. Place the steel former on the rammed bottom. Then fix the steel iron block at the center of the steel former to get uniform thickness throughout the furnace wall.

4. For ramming the upper portion of the side-wall just above the induction coil, mix the dry refractory material with 1-1.5% Sodium Silicate solution and 3-4% water.

5. Best results can be achieved by following the heating schedule for the furnace as mentioned hereunder -

Furnace Heating Schedule | Furnace Operation

Furnace Temperature	Rate of Heating with Holding Time
Ambient temp to 100OC	@ 30OC / hr.
Hold at 100OC.	4-6 hr depending upon the lining thickness.
100O - 800OC.	@ 50OC / hr.
Hold at 800OC.	2 - 3 hr.
800O - 1400OC.	@ 100OC / hr.
Hold at 1400OC.	4 - 6 hr.
1400OC to furnace operating temperature.	@ 100OC / hr.

Related Article

• Induction Furnaces | Channel Type and Coreless Induction Furnaces - Design, Advantages and Disadvantages 

Indian cement manufacturers ACC and Ambuja Cements implemented Blue Yonder for planning, logistics and digitalization | Cement Industry News

6-Feb-2021

Indian cement majors ACC Limited and Ambuja Cements Ltd., the two Indian cement manufacturing units of LafargeHolcim, recently announced that they have chosen Blue Yonder®, the world’s leading, end-to-end, digital supply chain platform provider, for their supply chain transformation and digitalization.

Both ACC and Ambuja Cement have implemented Blue Yonder Luminate Planning. Luminate Planning will help the two leading cement manufacturers in India improve Sales and Operational Planning (S&OP) with integrated planning and execution by gaining visibility into daily demand, production and dispatch plan to better predict demand fluctuation, scheduled maintenance, and improve logistics and transportation capabilities. With improved supply chain optimization, ACC and Ambuja Cement can better align the least cost service locations, reduce delivery costs and create a service network to meet and exceed customer service levels.

"We chose Blue Yonder as our partner for SCM digitalization because Luminate Planning will give us greater visibility into our combined supply chains,” said Rajeev Mehta, chief logistics officer, ACC and Ambuja Cement. “The objective of this project is to improve the customer experience and service levels, yet profitably grow by tapping into the synergies of our supply chains, thus maximizing capacity utilization and minimizing overall cost.”

The Blue Yonder Luminate™ Planning portfolio is a powerful set of solutions that continuously provides insights into a customer’s supply chain to allow for smarter, more actionable business decisions. Luminate Planning is built on Blue Yonder’s Luminate Platform, which is powered by Microsoft Azure and combines rich internal and external data from across a customer’s digital supply chain assets.

“As the leading cement companies in India, ACC and Ambuja Cement needed the ability to tap into their supply chains synergies,” said Vishal Dhawan, vice president, APAC sales, Blue Yonder. “With the end-to-end visibility afforded by Luminate Planning, the companies can better optimize their network and improve S&OP creating a more efficient supply chain.”

Ambuja Cements Ltd, a part of the global conglomerate LafargeHolcim, is one of the leading cement companies in India with about 29.65 MT cement manufacturing capacity in five integrated cement plants and eight cement grinding units across the country.

ACC Limited is India's foremost manufacturer of cement and ready mixed concrete with a countrywide network of factories and marketing offices.

Blue Yonder with offices in over 40 locations and 5000 associates are part of a diverse global community. Blue Yonder headquartered in Scottsdale, Arizona and has offices in major cities in the United States, Asia Pacific, Canada, Latin America, Europe, Australia, and the Middle East. Blue Yonder is the world leader in digital supply chain and omni-channel commerce fulfillment. Their intelligent, end-to-end platform enables retailers, manufacturers and logistics providers to seamlessly predict, pivot and fulfill customer demand. Blue Yonder services help in making more automated, profitable business decisions that deliver greater growth and re-imagined customer experiences.

Fosbel acquires Wahl Refractory Solutions | Refractory Industry News

 4-Feb-2021

Fosbel has announced the acquisition of Wahl Refractory Solutions, LLC. Fosbel headquartered in the United States, has regional locations in Germany, Brazil, Japan, India and South Africa.

Wahl Refractory Solutions, Fremont, Ohio, will now conduct business under the name Wahl Refractory Solutions, a Fosbel Company.

Wahl Refractory has been a respected manufacturer and supplier to the steel, aluminium, cement, and thermo-processing industries since 1921. A recognized leader in technology for monolithic refractories and precast refractory shapes, Wahl Refractory Solutions manufactures and provides customized refractory solutions. As the innovator in the use of steel fibres in refractories, Wahl Refractory pioneered SIFCA^® (Slurry Infiltrated Fibre Castable) and has been at the forefront in design, formulation, and manufacture solutions to customers’ toughest applications.

Read - Benefits of using Steel Fibers and Organic Fibers in  Refractory Castables and other Monolithic refractories

Fosbel’s mission in providing industry specific services, engineered refractory solutions and advanced installation methods will continue with good service to its markets by leveraging its employees to implement these strategies. The integration of Fosbel and Wahl Refractory secures a future of continued growth through strengthened products and services to a broader customer base.

By making a commitment to ensure Wahl’s continuing business under the Fosbel umbrella, capital investments are being made at Wahl Refractory Solution’s manufacturing plant. Fosbel will utilize Wahl Refractory’s manufacturing and production capabilities that will result in shortened supply chains and increased inventory capacities. This will result in improved products and services for Wahl Refractory and Fosbel customers.

Fosbel has been mainly engaged in providing following industry services -

Steel and Coke Services which include: CBM-Complete Battery Maintenance, Ceramic Welding, Inspection Services, Nano Tech CW Material, Custom Design Solutions, Repair Solutions, Blast Furnace Stoves, COMIT^® Condition Monitoring;

Glass Industry Services which include: CFM (Complete Furnace Maintenance), Ceramic Welding, Inspection Services, Hot & Cold Repairs, Furnace Life Asset Management & Evaluation etc.     

Both companies Fosbel and Wahl Refractory Solutions have been providing excellent customer service and new innovations to their respective markets by delivering consistent quality with repeatable performance.

Read - Indian Refractory Manufacturers: Are They Delivering Customer Delight

The Functions of Silica Fume (Microsilica) and other Ultrafine or Microfine Additives in Refractory Castables

The unshaped refractories, commonly known as Monolithic refractories are manufactured by suitably blending graded refractory aggregates, binders, fillers & (/or) special additives used for modification of ultimate properties. The refractory aggregates chosen for the formulation of refractory castables have a major contribution in determining their ultimate product quality. Along with this and many other input parameters, especially the high temperature properties of all type of Castables (Aluminous / Basic) depend a lot on the additive’s level and type used. All ingredients, binders, and additives of different chemical compositions and grading are chosen, blended to provide the proper characteristics for various applications of monolithics. 

Effect of Water Addition vs. Ultrafine Additives (Silica Fume) in Castable Refractories

For castable refractories the mobility of various particles is essential for proper placement of the castable. One method to achieve mobility is by adding more water, but this increases porosity & thus affects the performance both at normal & elevated temp. Therefore, addition of water should be minimized. The desired fluidity can be achieved by maintaining the coarser particles separated from one another by suspension of fines and ultrafine additives combined with the state of flocculation within the suspension. The role of the grains of these ‘Microfines or Ultrafine Additives’ can be compared with those of the balls in a ball-bearing.

What are the commonly used Ultrafine Additives in Refractory Castables?

Read: Benefits of using Steel Fibers and Organic Fibers in  Refractory Castables and other Monolithic refractories

The commonly used microfines or ultrafine additives are Silica Fume also known as Microsilica or Fumed Silica, microfine Alumina (Al₂O₃), ultrafine green Chrome Oxide (Cr₂O₃) etc. Silica fume is a by-product of producing silicon metal or ferrosilicon alloys. Silica fume consists primarily of amorphous (non-crystalline) silicon dioxide (SiO₂). Because of its super fine particles, large surface area, and the high SiO₂ content, silica fume is a very reactive.

The addition of Microsilica or Silica Fume has other advantages also, since these micro fine silica particles easily react with alumina present in the material to form Mullite which, in turn, helps in enhancing refractory properties of the product.

The addition of certain percentage of superfine green Chrome Oxide (Cr₂O₃) in Alumina castables increases the slag corrosion resistance & HMOR of the product significantly because of the formation of Alumina-Chrome (Corundum) solid-solution.

There are several manufacturers of fumed silica. Some well-known global brands of fumed silica are of Elkem Materials, AEROSIL of Evonik Industries, Norchem Concrete Products. 

 

Read: Advantages of using Gel Bond and Colloidal Silica in Monolithic Refractories