High temperature flue gas corrosion and protective measures in Xingtai Calcium Silicon Smelter

The silicon calcium alloy is prepared by reducing silicon dioxide and calcium oxide with carbon reducing agent in the reduction electric furnace. The main raw materials in the production process are quartz (SiO _two ）, limestone (CaCO _three ）And reducing agent mixture (mainly coke and bituminous coal).

There are two main reactions:

CaO 2SiO _two 　5C→CaSi _two (Alloy) 5CO (1)

Meanwhile, the reaction of production slag shall be avoided:

2CaO SiO _two →2Ca0•SiO _two (Slag) (2)

Thermodynamically, reaction (2) can be produced at low melt temperature, while reaction (1) can only occur at 1600 ℃ or above. In order to support reaction (1) more than reaction (2), the melt temperature should be above 1800 ℃. Generally, the flue gas from silicon calcium alloy smelting has higher temperature, larger flow and more heat, so the waste heat power generation system is generally built. The flue gas contains many corrosive substances, such as sulfur dioxide (SO _two ）And other acid gases, as well as abrasive soot particles. In high temperature environment, the corrosion effect of these substances is more significant, which will cause damage to waste heat boiler, heat exchanger, flue gas treatment and other equipment. For example, waste heat boilers and heat exchangers, dust collectors, desulfurization towers, etc. will be severely corroded, resulting in equipment performance degradation, shortened life, and even safety accidents.

In order to reduce the corrosive impact of submerged arc furnace flue gas on equipment and environment, effective anti-corrosion measures need to be taken, usually 1041 flue gas anti-corrosion coating is selected. ZS-1041 flue gas anti-corrosion coating produced by Beijing Zhisheng Weihua Chemical Co., Ltd. is based on inorganic siloxane Si-O-Si bond as the main chain, grafted with a variety of organic functional group side chains as the auxiliary anti-corrosion film-forming material as the main substrate, flake graphite filler as the aggregate, and added with various functional additives to mix into a clay like or coating like anti-corrosion material. ZS-1041 flue gas anti-corrosion coating has good temperature resistance up to 750 ℃. The coating contains ultra-fine wear-resistant micro powder, which has a hardness of more than 7H after curing, and can withstand the erosion and abrasion of dust and asphalt smoke for a long time. It is durable for at least 10 years under high temperature flue gas and dust environment!

In addition, ZS-1041 flue gas anti-corrosion coating also has other advantages, such as the use of inorganic ceramic fiber in the coating, which increases the internal cross strength of the coating and enhances the impact resistance of the coating. The paint is also equipped with appropriate solvents, additives and wear resistance enhancers. Through the interaction and synergistic effect of each component, the coating has comprehensive excellent properties such as low surface energy, high corrosion resistance, high hardness and strong adhesion with the substrate.

For the anti-corrosion problem in the flue gas treatment equipment of submerged arc furnace, selecting ZS-1041 flue gas anti-corrosion coating is a very recommended solution. The application of this coating can effectively extend the service life of flue, dust collector, waste heat recovery and other equipment, reduce maintenance costs, and improve production efficiency and safety!