HZX-5000 series DC electric arc furnace - Solid and dangerous waste

Rock wool, mineral wool industry status:

Industrial waste disposal has always been the focus of attention of domestic and foreign enterprises. In 2018, the state promulgated the solid waste discharge standards, how to deal with industrial waste, how to comprehensively utilize industrial waste has become a problem faced by domestic enterprises. The hot industrial waste slag contains a lot of sensible heat, according to statistics (taking blast furnace slag, silicon manganese alloy slag, nickel iron slag as an example) each ton of hot slag containing waste heat is about 50KG of standard coal generated heat, each ton of hot slag waste heat can generate electricity about 90KW·h ~ 100KW·h, how to use this part of sensible heat is our research direction.

Mineral wool (or rock wool) is a kind of artificial inorganic fiber, it has light weight, small thermal conductivity, strong heat resistance and non-combustible and other excellent properties. This is commonly used insulation materials, such as vermiculite, perlite, diatomite, foam cement, etc., is difficult to fully compare with it. Mineral (rock) cotton adding a special binder can be made of flexible or semi-rigid products, such as mineral wool shell, mineral wool board, mineral wool felt, etc. These products can be widely used in petroleum, electric power, metallurgy, chemical industry, construction and transportation and other industries, can also be used as sound absorption and sound insulation materials.

Hot melt slag production process of mineral wool:

The advantages and disadvantages of producing mineral wool and rock wool by electric furnace:

Advantages:
(1) The equipment has strong applicability, easy to start, stop, power off, etc., simple operation;
(2) Equipment investment is relatively small, easy to repair and maintain;
(3) High heating efficiency (heating temperature can reach more than 2000℃);
(4) Low energy consumption (compared to the traditional process saving 300Kg ~ 350Kg coke);
(5) High working efficiency, can work continuously for 24 hours, do not need frequent furnace shutdown;
(6) The requirements for raw materials (generally require raw material particles in 1mm-5mm);
(7) The production waste can be reused, and the waste slag treatment rate can reach more than 90%;
(8) Low environmental requirements, less flue gas emissions (mainly smoke 350mg/m²), easy to recycle.
Cons:
(1) High one-time investment;
(2) Add mixing material with hot slag production, which is not easy to melt evenly;
(3) The lining life is short (generally 3 months -4 months repair).

Key technical process:

Treatment Principles

• High - temperature Melting and Pyrolysis: The electric arc furnace can generate a high - temperature environment of 1600 - 2000°C. In this environment, organic components in solid and dangerous waste are pyrolyzed and decomposed into simple substances such as carbon and hydrogen, while inorganic components are melted.
• Chemical Reaction and Impurity Removal: For some solid waste containing metal impurities, high - temperature can promote chemical reactions between impurities and added fluxes. For example, in the treatment of electric arc furnace steel - making dust, lime powder is added, and under high - temperature conditions, it reacts with some metal oxides in the dust to form fusible slags, which are then separated from the molten metal or other useful components.

Process Flow

• Waste Pretreatment: Solid and dangerous waste needs to be pretreated before entering the electric arc furnace. This may include sorting, crushing, and drying to ensure that the waste can be evenly heated and reacted in the electric arc furnace. For example, electric arc furnace steel - making dust needs to be collected through a sealed dust - removal pipeline and then ground in a dust - closed pretreatment device.
• Feeding: The pretreated waste is fed into the electric arc furnace. The feeding method can be continuous or batch - type, depending on the type and treatment volume of the waste and the characteristics of the electric arc furnace.
• High - temperature Treatment: After the waste enters the electric arc furnace, it is heated by the arc to undergo high - temperature melting, pyrolysis, and other reactions. During this process, the organic matter in the waste is decomposed, and the heavy metals are either volatilized or remain in the molten slag or metal phase.
• Product Separation and Treatment: After the treatment is completed, the materials in the electric arc furnace are separated. The molten metal can be further refined to obtain high - purity metals; the molten slag can be cooled and crushed, and some slags can be used as building materials or recycled after further treatment; the volatilized gas needs to be treated through a gas - treatment system to remove harmful substances and then discharged or recycled.

Application Scenarios

• Treatment of Electric Arc Furnace Steel - making Dust: Electric arc furnace steel - making dust is a typical solid hazardous waste. It contains about 40% iron, 10% zinc, and trace amounts of heavy metals such as lead, chromium, and cadmium. By using the electric arc furnace self - circulation consumption and utilization method, the dust can be mixed with carbon powder and lime powder and sprayed into the electric arc furnace molten pool. The iron in the dust is reduced and enters the steel liquid, while the zinc is reduced and enters the regenerated dust. When the zinc content in the dust reaches 25% - 30%, it can be used as a raw material for zinc - smelting systems.
• Treatment of Organic Hazardous Waste: The electric arc furnace can also be used to treat organic hazardous waste such as waste plastics, animal carcasses, medical waste, and asbestos waste. Under high - temperature conditions, organic hazardous waste is pyrolyzed and decomposed, and the final products are harmless gases, carbon - containing substances, and glass - like substances, achieving harmless treatment and resource utilization.

Advantages

• High - efficiency Harmless Treatment: It can quickly decompose and destroy organic pollutants and stabilize heavy metals in a high - temperature environment, with a high degree of harmless treatment. For example, when treating organic hazardous waste, the volume of waste after treatment can be reduced by up to 99.7%.
• Resource Utilization: It can recover valuable metals in waste and convert some waste into reusable materials such as building materials, realizing resource utilization.
• Strong Adaptability: It can adapt to various types of solid and dangerous waste, including waste with complex components and high - toxicity waste.

  Shaanxi Chengda Industrial Furnace Manufacturing Co., Ltd. is a high-tech enterprise specialized in the research, design, and manufacturing of various industrial furnaces, including AC and DC steelmaking electric arc furnaces, ladle refining furnaces, ferroalloy ore thermal furnaces, ferroalloy refining furnaces, electric slag remelting furnaces, non-standard metallurgical equipment, heat treatment equipment, and various related environmental protection dust removal equipment. The company's product design and manufacturing capabilities have reached 100 tons for electric arc furnaces, 160 tons for ladle refining furnaces, and a capacity range of 3600KVA to 35000KVA for ore thermal furnaces. In accordance with national industrial policies, we have designed high and low voltage compensation systems, dust removal systems, ferroalloy DC furnaces, and new energy equipment suitable for the actual operation of the equipment. For inquiries, please contact Mr. Du at 13991381852 or Mr. Chen

13709182307.