Steel slag grinding in industrial use

Steel slag is produced during the separation of the molten steel from impurities in steel-making furnaces. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling.Steel Slag is a valuable resource for society. Blast furnace slag which is naturally cementitious for the cement industry.

　　A super-fine steel slag with the specific surface area of 786 m2/kg was prepared by mechanical grinding. Its cementitious properties were investigated by comparing the results obtained from it with those obtained from ordinary steel slag, fly ash, and cement. The results show that the super-fine steel slag exhibits a much higher activity at early and middle ages but a lower activity at late ages than the ordinary steel slag. Though the specific surface area of the super-fine steel slag is much larger than that of cement, the activity of the super-fine steel slag is still obviously lower than that of cement. The super-fine steel slag replacement tends to weaken the cementitious properties of the composite binder. As compared to fly ash, the super-fine steel slag tends to make more contributions to the hardening of concrete at early ages but far less contributions at late ages. Overall, it seems that it is uneconomical to produce super-fine steel slag by mechanical grinding.

　　The product of the Great Wall machinery production steel slag vertical roller mill is the equipment to grind Ground Granulated Blast furnace Slag into small particles.steel slag(fineness:4200-4500cm2/g) produced by vertical roller mills are being used to substitute clinker in conventional cement manufacturing as well as to partially replace OPC for ready-mixed concrete production, for which the percentage of GGBS usage is typically at 10-15% and 20-25% respectively.

　　The product of the Great Wall machinery production steel slag vertical roller mill is the equipment to grind Ground Granulated Blast furnace Slag into small particles.steel slag(fineness:4200-4500cm2/g) produced by vertical roller mills are being used to substitute clinker in conventional cement manufacturing as well as to partially replace OPC for ready-mixed concrete production, for which the percentage of GGBS usage is typically at 10-15% and 20-25% respectively.

How to deal with the rotary kiln gear problem of apical teeth

As well known, rotary kiln is an equipment support by supporting roller and drove by transmission gears. There are many factor and fault may leads the phenomenon of apical teeth, for example, the abrasion between riding ring and kiln pads, riding ring and support roller, roller shaft and bearing bus, the kiln shell’s transformation and the support roller’s adjusting, etc. This phenomenon will result in the shake of rotary kiln, costs more motor power consumption, and the bolt become loss. What is more, it may result in the falling off of the rotary kiln.

　　As a famous large steel casting foundry, Great Wall Steel Casting can handle this problem with years experiences and concluded as follows:

　　1. Outside move the small gear. Move the small gear up may make the gap bigger. It take advantage of the reservation of bolt hole on reducer seat and motor seat. It is easy and intuitive but with the shortcoming of less adjustment amount.

　　2. Add pads under the roller seat. Put more pads under the roller seat and engine base allows the kiln central place uplift. This method can only be executed when kiln stop working. And the rotary kiln shall be jacking by jack. Though this work is complicated, but it is free of the limit form roller’s stress state. Therefore, it is better for those who have large adjustment amount.

　　3. Push the roller inward. This can uplift the kiln centre and make the gap between gears larger than before. It can be executed when rotary kiln is working. But there not too much places for push.

　　Take any of the method mentioned above can achieve the aim that adjust the gap between gears. Great Wall Steel Casting is one of the biggest steel casting foundries in China. When supply the casting products, we also offer the best solutions for your technical problem. Welcome to contact us for more of your enquiries. If you need to Purchase large steel castings, Make your decision after visit Great Wall.

What is GGBS?And the usefulness of GGBS!

Ground granulated blastfurnace slag (GGBS) is a by-product from the blast-furnaces used to make iron. These operate at a temperature of about 1,500 degrees centigrade and are fed with a carefully controlled mixture of iron-ore, coke and limestone. The iron ore is reduced to iron and the remaining materials form a slag that floats on top of the iron. This slag is periodically tapped off as a molten liquid and if it is to be used for the manufacture of GGBS it has to be rapidly quenched in large volumes of water. The quenching, optimises the cementitious properties and produces granules similar to a coarse sand. This 'granulated' slag is then dried and ground to a fine powder.

　　Although normally designated as "GGBS" in the China, it can also be referred to as "GGBFS" or "slag cement"

　　blast-furnace slag

　　Through the use of vertical grinding mill for grinding slag, waste slag grinding into slag powder.

　　The major use of GGBS is in ready-mixed concrete, and it is utilised in a third of all China ‘ready-mix’ deliveries. Specifiers are well aware of the technical benefits, which GGBS imparts to concrete, including:

　　•better workability, making placing and compaction easier

　　•lower early-age temperature rise, reducing the risk of thermal cracking in large pours

　　•elimination of the risk of damaging internal reactions such as ASR

　　•high resistance to chloride ingress, reducing the risk of reinforcement corrosion

　　•high resistance to attack by sulphate and other chemicals

　　•considerable sustainability benefits

　　In the production of ready-mixed concrete, GGBS replaces a substantial portion of the normal Portland cement content, generally about 50%, but sometimes up to 70%. The higher the proportion, the better is the durability. The disadvantage of the higher replacement level is that early-age strength development is somewhat slower.

　　GGBS is also used in other forms of concrete, including site-batched and precast. Unfortunately, it is not available for smaller-scale concrete production because it can only be economically supplied in bulk. GGBS is not only used in concrete and other applications include the in-situ stabilisation of soil.

vertical roller mill production from Great Wall

What are the advantages of Cement kiln disposal of sewage sludge

The advantages of disposal of sewage sludge by cement kiln than by professional incinerator

　　High treatment temperature

　　Temperature in cement kiln can reach 1800 ℃,the burn rate of harmful ingredient in the mainly organic matter can up to 99.999%, even the stable organic matter can also be completely decomposed

　　Burning atmosphere stable

　　Cement kiln is a large rotary cylinder, not only can handle large amounts of waste, and can maintain a homogeneous, stable burning atmosphere.

　　Long Incineration

　　Sludge stay a long time at the high temperature furnace, burning fully.

　　Large-scale treatment

　　New cement kiln treatment sludge accounted for about 2% of kiln production.

　　Alkaline cement kiln atmosphere

　　Avoid "secondary pollution" resulting by burning exhaust gas of common incinerator

　　Cement kilns burning hazardous waste

　　Allows solidification of potential presence metal elements in hazardous waste, plays a dual role of exhaust gas purification and heavy metals high temperature curing in mineral admixture.

　　Cement kiln system is operated in Negative pressure

　　Smoke and dust will not spill out, to prevent the re-contamination radically in the process.

　　Cement kiln treatment sludge

　　Because of the sulfur absorption effect of theburning process, integrated emissions of pollutants was improved and reduced.

　　Refractory bricks in Cement kiln

　　Firebrick, raw materials, kiln coating and clinker are alkaline, can absorb SO2, thereby suppressing their emissions.