Published at 2022-06-11, published by cyanbat | Keywords: magnesium Production process
With the continuous progress of society and the continuous improvement of science and technology, the production process of metal magnesium has become more and more mature.
Overview of the production process of magnesium metal: dolomite is crushed by a crusher to qualified materials (30-40mm), sintered in a rotary kiln, calcined into calcined white, cooled by a cooler, then ground into powder by a ball mill, and then pressed by a briquette machine.
Formed into balls, after crushing, mixed with ferrosilicon powder (containing 75% silicon) and fluorite powder (containing GaF2) = 95% to form a ball, put into a heat-resistant stainless steel reduction tank, placed in a reduction furnace, at 1200- 1250C and 1.33Pa vacuum degree of vacuum reduction to prepare crude magnesium, through solvent refining, ingot casting, surface treatment to obtain finished magnesium ingots.
With the continuous progress of society and the continuous improvement of science and technology, the production process of metal magnesium has become more and more mature. As far as the current situation is concerned, the production process of magnesium metal can be roughly divided into two main methods, one is the thermal reduction method, and the other is the electrolysis method. These two methods can be subdivided into several different methods. Methods. Each method has its advantages and special uses.
1. Introduction of thermal reduction method in the production process of metal magnesium: the application of thermal reduction method mainly uses the chemical substance silicon to realize the purification of metal magnesium. The raw materials used in the production process include silicon carbide, calcium oxide and pure silicon.
The conditions required for the chemical reaction produced are high temperature and vacuum. At high temperature, the temperature should reach 1100~1250 degrees Celsius. The thermal reduction method we know is divided into several different methods according to the different reaction equipment required, but their principles are the same. According to different equipment, it is divided into four different methods, namely Pijiang method, Balzano method, Magni method and MTMP method. Now we will discuss these four methods first.
2. Introduction of the Pidgeon method for the production of magnesium metal: The Pidgeon method is a typical method of producing magnesium metal. The raw materials required in this method include dolomite ore, fluorite, silicon ore, coke and scrap iron. In the production process, the dolomite ore is calcined in a rotary kiln to form white jade, which is then pulverized, and then the fluorite is pulverized. , the scrap iron is put into the electric arc furnace for reaction and then pulverized to generate ferrosilicon powder, which is put into the pelletizing machine with the mixture in the mixer, and then put into the reduction furnace and the pellets containing ferrosilicon and fluorite are added. The reaction produces magnesium crystals, which are then melted and purified to produce metallic magnesium. The production time period of this method is about 10 hours. Its technological process is divided into three stages, including preheating period, low vacuum heating period and high vacuum heating period.
3. Process flow of metal magnesium production Introduction of Balzano method: Balzano method is developed on the basis of Pidgeon method. Its basic technological process is very similar to Pidgeon method, but some places are different. The main difference is that he does not press the dolomite and ferrosilicon into agglomerates during the reaction process, but directly uses an electric heater to heat them, which is a relatively energy-saving method. This approach was used by a company in Brazil.
4. Introduction of Magni method for magnesium production process: Magni method was discovered around 1960. In our opinion, the most notable feature is that it adopts a method that is more energy-saving, but its reaction cycle is relatively Compared with the Pidgeon method, which takes ten hours to sleep, the reaction time is almost twice as long, usually 16 to 24 hours. In the reaction container, the form of the substances in the container is generally liquid, and the reaction temperature is also relatively high, generally exceeding the upper limit of the Pidgeon method, which is 1300~1700 degrees Celsius. During the production process, magnesium metal is produced in the form of gas or liquid and in the condenser.
5. Introduction of MTMP method for metal magnesium production process: MTMP method is a more continuous production technology for manufacturing metal magnesium. In the manufacturing process, his reaction temperature is higher, 1700~1750 degrees Celsius, and finally the formation of metallic magnesium is also generated in the condenser. The above four are some of the effects that the thermal reduction method of metal magnesium can achieve under different production equipment and production conditions.
6. Electrolysis As far as we are advocating energy saving requirements, electrolysis may be more popular with us, because the production process of electrolysis is relatively advanced and simple, and has the characteristics of low energy consumption. The core of the electrolysis method is to use direct current to electrolyze molten anhydrous magnesium chloride to decompose it into magnesium and chlorine gas. As far as the electrolysis method is concerned, it can be divided into different methods according to the raw materials that are not used. Generally, it can be divided into Daowu method, magnesium oxide chlorination method, AMC method and so on. Next we discuss some of these in detail.
7. Introduction of Daowu method of magnesium metal production process: Daowu method is a relatively simple electrolysis method, and its raw materials are also easy to obtain. The raw materials include sea water and lime milk. These two raw materials are used to extract magnesium hydroxide, and then it is chemically reacted with hydrochloric acid to generate a solution. Electrolysis is performed. This method is a relatively simple production method, which is energy-saving and also cut costs.
8. Introduction of chlorination method of magnesium metal production process: The raw material of magnesium oxide chlorination method is carnallite. After passing through the fluidized bed, it is added to coke and chlorine and then put into the chlorination furnace. Electrolysis is performed to generate chlorine gas, metal magnesium, and potassium chloride, and the generated chlorine gas is collected for chlorination reaction, realizing recycling, saving resources, and realizing energy saving. In addition to these two methods, there are several other methods of electrolysis. One of the most characteristic is the snooker method, which uses magnesium chloride to extract metallic magnesium under high pressure and electrolysis. Especially because it is unique and does not use a chlorination reaction to make the raw material for magnesium production.
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Source: @cyanbat Author: cyanbat