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Showing posts with label Industry Guru. Show all posts
Showing posts with label Industry Guru. Show all posts

HeidelbergCement India - Lackluster Q1 performance due to covid lockdown restrictions

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22-July-2020
CEMENT INDUSTRY NEWS | INDUSTRY GURU
HeidelbergCement India Ltd on Wednesday reported a 38.07 per cent decline in net profit at ₹ 48.94 crore for the first quarter ended June 2020.
The company had reported a net profit of ₹ 79.03 crore in the April-June 2020 period of the preceding fiscal, HeidelbergCement India said in a BSE filing.
Total revenue from operations declined 30.80 per cent to ₹ 407.70 crore from ₹ 589.23 crore in the corresponding quarter of 2019-20.

The company said its sales volume declined due to suspension of operations during covid lockdown period. "Volume decreased by 32 per cent, primarily driven by the suspension of operations in April 2020. The decrease in volume impacted revenue and profitability during the quarter," said HeidelbergCement India, a subsidiary of HeidelbergCement Group.
Cement sales volume during the quarter was 857 KT as against 1,258 KT earlier. Total expenses were at Rs 342.99 crore as against Rs 479.25 crore in Q1 FY20, down 28.43 per cent.
In an interview to ET Jamshed Naval Cooper, MD of HeidelbergCement India Ltd said, capacity utilization will be hovering between 55% and 60%. Today many of the cement companies will have a very high breakeven.
You cannot keep a cement processing plant shut continuously. We made a big mistake of having a lockdown in the cement plant, he said. However, he is hopeful that after Diwali (which falls in November this year), most migrant labourers will return and capacity utilisation of cement plants should touch 70%.


Use of Kyanite as Refractory Raw Material

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21-July-2020


Kyanite is one of the Alumino-Silicate group of minerals comprising Sillimanite, Kyanite, Andalusite, Dulmortierite, Topaz and Mullite all with similar chemical composition but different physical behavior and hence, uses. Kyanite, raw as well as calcined, have separate applications as refractory raw materials because of their distinct characters. 

Raw Kyanite

Industry Guru - image of raw kyanite
Raw Kyanite (Refractory Grade)
To be suitable for refractory raw material, kyanite should have very negligible amount of impurities which include free silica, alkali, iron oxides, calcium and magnesium. Kyanite, Sillimanite and Andalusite all these three minerals convert to Mullite and silica when they are calcined to temperatures between 1250OC and 1500OC. The inversion kyanite to mullite and silica (glass) begins at the periphery of grains and this rate of conversion depends the following:
>> Particle size
>> Firing temperature
>> Soaking time
>> Impurities present.
The heating of raw kyanite is accompanied with its volume expansion and a decrease in its specific gravity from 3.6 to 3.06, which takes place over a small range of temperature around up to 1350OC. 
Because of this property raw kyanite - 
  • Raw kyanite is extensively used for making high alumina insulation bricks, insulating mortars and castables.
  • Raw kyanite fines (pulverized) can be added to refractory mixes in different proportions as a measure to control or compensate the overall shrinkage due to other raw materials. 


Calcined Kyanite

Industry Guru - image of calcined kyanite lumps
Calcined Kyanite (lumps) to be used in making Refractories
In order to make it a volume stable refractory material, kyanite is pre-calcined at 1420OC to mullite and Cristobalite before use. Sometimes the lumps are very hard to crush after calcination. To avoid this, after calcination the kyanite lumps are, sometimes, quenched in water to make them crumble easily. Thereafter, it is ground, graded into various fractions as per requirement. These grains of calcined kyanite being volume stable are used with other raw materials for making refractory bricks and castables. The various refractory properties are:
P.C.E - above 1785OC or 35+ (Orton)
RUL (refractoriness under load) - 1750OC
Porosity = 24 - 25%
Properly calcined kyanite is a very good refractory raw material because of its high alumina percentage and low iron contents. As compared to other refractory raw materials kyanite can be sometimes, very handy for boosting alumina content and other refractory properties of the product at the same time maintaining its cost effectiveness.
Refractories made from calcined kyanite possess:
  • Higher modulus of rupture and creep resistance
  • Lower co-efficient of expansion
  • High thermal shock resistance
  • Increased durability, about three times that of ordinary bricks
  • Superior resistance to salt attacks and chemical corrosion
  • Very low co-efficient of spalling
Related Article: Kyanite - Properties and Indian Occurrences

HYL III and SL/RN - The two widely accepted Direct Reduction (DR) Processes of ironmaking

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10-Oct-2009

Direct Reduced Iron (DRI) is obtained by reducing lumps as well as fines of iron ore in solid state at a relatively low temperature of around 1000OC. A large number of DR processes are available today. SL/RN and HYL are two such DR processes. While HYL is a batch-type gas based process and uses a countercurrent shaft-furnace, the SL/RN process utilizes rotary kiln to reduce lump ore, pellets and sand iron with coal. Here we will discuss about some key features, including advantages and disadvantages of these two DR processes.

HYL III
https://www.industry.guru
Fig: HYL III Process Scheme


The HYL process was developed in Mexico and was the forerunner of the HYL III direct reduction technology. In HYL I process, a mixture of gases containing about 89% of reducing compounds is used. Each reduction module in HYL plant consists of four units - three “in line” and the fourth in “turn around” mode. The principal change made over HYL I in HYL III was the modification of the four fixed bed reactors by a single moving bed reactor, utilizing the same gas reforming plant, auxiliary equipment and quenching towers.  Actually HYL III technology is characterized by its wide flexibility for adapting to special needs, depending on available reducing gases, energy use and melt-shop requirements. Use of spent gases from direct ironmaking processes, coal gasification, energy optimization in DR plants and technology developments aimed to improve EAF productivity have been the objective of HYL. Some distinctive features of HYL III process are:

Fig: HYL III - COREX Off-Gas Process Scheme
=> The H2/CO of the reformed gas is 3, the temperature is about 930OC, the inside pressure of the countercurrent shaft-furnace is 450 kilopascals and the energy required for the reduction is basically the same as in the MIDREX process.
=> The selective elimination of H2O and CO2 from the reducing gas circuit allows maximum recycle of the reducing gases to the reduction reactor. Hence, the reducing gas make-up and the process natural gas consumption are minimized.
=> The reducing gas generation and the reduction sections of a HYL III unit are independent from an operational point of view. This feature offers important flexibility for adapting to different reducing gas sources. The process schemes based on use of alternative reducing gases from different sources and other DR/ Ironmaking sources have been proven in HYL III plants. Such alternate sources of reducing gas can be -
  • Coal gasification processes.
  • Coke oven gas.
  • Gases from Hydrocarbon gasification.
  • Partially spent gases from another DR plant.
  • COREX off-gases.
=> High pressure operation (4 atmospheres or more) enables the effective control of process conditions, with smaller equipment size for gas handling and lower energy requirements (9.0 - 10.0 GJ/t).
=> The process is much flexible as far as raw material use is concerned - while it operates best with 100% pellets, even 100% lump ore of a suitable type has been used, but it is suggested to use a mixture of pellets and lump ores.   
=> This technology offers the unique flexibility to produce three different product forms depending on the specific requirements of each user - Cold DRI, HBI and HYTEMP iron. Metallization can be controlled up to 95% and Carbon content 5.0%.
=> When combined with COREX off-gas as a source of reducing gas, the HYL III DR plant offers high productivity using available spent gas and benefits in steel production using HYTEMP® iron together with hot metal in EOF/BOF based steel mills.
=> The HYL III process features the flexibility of generating electric power, taking advantage of high pressure steam produced in the natural gas-steam reforming unit which can be used in a turbo generator or in a set of turbines, at a high generation capacity.
According a data of recent past, around 11 million tones of direct reduced iron (DRI) was produced in 2003 by this process in India, Grasim’s HYL plant at Raigad (Orissa) produced 0.75 million tones of HBI.     

SL/RN
SL/RN is the most widely accepted coal based DR process. It was jointly developed by Stelco, Lurgi Chemie, Republic Steel Company and National Lead Corporation in 1964. In this process, the materials charged into the kiln gravitate towards the discharge end during which they are progressively heated to the temperature of reduction of around 1000 - 1100OC. The product discharged from the kiln is cooled in an extremely cooled rotary cooler around 100OC before being subjected to magnetic separation to separate sponge iron from coal ash and char. Waste gases leaving the kiln at the inlet end pass through a dust chamber and a post combustion chamber, before being cooled and cleaned in electrostatic precipitators, scrubbers or bag filters. In SL/RN technology the clean gases can be used in waste heat boilers to recover the sensible heat and the steam generated can be utilized for heating purpose or for electric power generation. Some distinctive features of SL/RN process include:
=> Flexibility with regard to the type of iron bearing materials which can be used such as lump ore, pellets, ilmanite, iron sands and steel plant wastes.
=> Use of a wide variety of solid fuels ranging from anthracite to lignite and charcoal.
=> Improved heating of the charge by submerged air injection in pre-heating zone of the kiln. This process suffers, however, from relatively big heat loss and facility size.
=> SL/RN technology provides optimized coal injection facilities at the discharge end of the kiln.
=> Waste gas conditioning by controlled post combustion followed by power generation (the power generated is more than the requirement of the plant).
The original SL/RN process has been modified in a variety of ways, particularly in India where rotary kiln DR technology has been widely applied.