A Brief Discussion on the Production of Active Lime Factory and Its Role in Steelmaking

With the continuous development of economic globalization, competition in the steel active lime market has become increasingly fierce. Traditional slag-making raw materials such as silicate or fluorite are used in the steelmaking process, and their effects can no longer meet the needs of the steel market. In order to speed up the slag formation rate in the steelmaking process, active lime is used in steelmaking. Activated lime has strong chemical properties and ability to participate in the reaction, and the content of harmful impurities is low. Therefore, active lime is used in steelmaking.

　　 1. Overview of active lime

　　 Because active lime has high reactivity, it can quickly and completely dissolve with molten steel in a short time. During the steelmaking process, the molten steel reacts with different substances to produce harmful substances, namely steel slag. To ensure the quality of steel, slag removal is required. The effect of adding limestone into molten steel as a slag-forming agent is significantly higher than that of silicate or fluorite. However, it also has a defect. Limestone is prone to endothermic reaction when exposed to high temperature, that is, calcium carbonate decomposition reaction, and requires a lot of heat, and slagging is delayed. Because the molten steel cools quickly, the decomposition reaction of calcium carbonate not only absorbs a large amount of heat, but also delays the slagging time, so that when the slagging starts, there is a shortage of heat. This not only prolongs the steelmaking time, but also increases the consumption of raw materials, and the quality of slagging will also be reduced. Therefore, it is proposed to first calcinate limestone into lime, and then use it in steelmaking.

Active lime manufacturers

　　 Lime powder can also be called calcium carbonate. Calcium carbonate active lime manufacturers are a very common mineral in our lives. It is mainly the main component of limestone and calcite. The use of limestone has a long history. A white powdery substance with calcium carbonate as the main component. The application range is very wide, the most common is calcium carbonate used in the construction industry, that is, industrial use; the other is food-grade calcium carbonate, which is widely used as a common calcium supplement. There are two commonly used calcium supplements-calcium carbonate: one is heavy calcium carbonate, which is crushed to a certain degree of fineness and used as food additives; the other is light calcium carbonate, which is made by calcining limestone have to.

   (1) Determination of lime activity by acid-base titration.

   (2) Index of lime activity

An index that characterizes the hydration reaction rate of quicklime, that is, in sufficient time, it is expressed in milliliters of 4mol/L hydrochloric acid consumed to neutralize the Ca(OH)2 produced during the digestion of quicklime.

    (3) The definition of the activity of lime: the structure of lime is closely related to the calcination temperature and calcination time. The organization structure that affects the activity of lime includes bulk density, porosity, specific surface area and grain size of CaO minerals. The smaller the crystal grains, the larger the specific surface area, the higher the porosity, the higher the lime activity, and the stronger the chemical reaction ability.

   (4) Application: Steelmaking practice shows that the price of this kind of active lime can increase the dephosphorization and desulfurization efficiency by 80%, while shortening the smelting time. It can completely react with the acidic substances in the molten steel within 3-5 minutes. The response time should be at least 6-10min. In addition, the furnace age is increased by more than 40%, and the consumption of charge is also reduced by 5-8kg/t steel. Calculated by 10 million tons, it saves about 15 million per year, and the production benefit is significant.