Low ferrosilicon for casting is made of bauxite and coke (anthracite) as the main raw materials. It is smelted in an electric arc furnace at a high temperature of 2000 degrees. The microhardness is HV1800-2200. It can be used to make abrasive tools and is suitable for grinding resistance metals with higher tension, such as various general-purpose steels, malleable cast iron, hard bronze, etc., can also be used to manufacture high-grade refractory materials.
There are many ways to produce low ferro-silicon for foundry. Low ferro-silicon for foundry is formed from high-alumina bauxite raw ore and alumina with loose structure through the steps of batching, grinding, molding, drying, and firing. This includes the following steps:
a. Crushing, batching, and grinding. Break the bauxite raw ore into particles, mix it with binder, alumina and water, and grind it into fine particles to obtain material A;
b. Iron removal through the iron remover. Carry out deironing treatment, obtain B material;
c. filter and dehydrate B material in the filter mud machine, obtain filter cake C;
d. Vacuum mud refining Use a vacuum extruder to carry out vacuum mud refining on the filter cake C, and form a single billet D after extrusion and cutting;
e. drying and sending the billet D into a drying device for drying to obtain material E;
f. firing and sending the material E into a kiln for firing to obtain low ferrosilicon for casting .
The production of low ferrosilicon for foundry includes the following steps:
a. aluminum ore is heated and calcined in a kiln to obtain bauxite;
b. bauxite discharged from the kiln can be directly added to the smelting furnace at a temperature;
c. bauxite It is continuously heated in a smelting furnace and smelted to produce low-silicon iron for casting.
A kind of production method of polyaluminum chloride, its technique is to pulverize low-grade bauxite to 60 orders, put in rotary kiln and roast at 600-700 DEG C of temperature for 1-3 hours, take out and cool to 200-300 DEG C Put it into the reactor at 0°C and add concentration to be 25-30% hydrochloric acid to carry out acid dissolution, control the stirring reaction time under the pressure of 0.2-0.3MP for 6 hours, the reaction temperature is controlled at 120-130°C, and the activated bauxite the weight ratio with hydrochloric acid is 2:3. Low ferrosilicon for foundry adopts steps such as cycle activation, leaching, carbon, sodium carbonate and water recovery, silicon-aluminum separation, pyrolysis, hydrochloric acid recovery and other steps. The CO2 produced in the whole process and the alkali used in the extraction process, Both acid and water can be recovered and recycled. The above-mentioned production methods each have different characteristics.
Production of low ferrosilicon for foundry combined with energy-saving and consumption-reducing new production methods to improve production efficiency includes: refining and purifying alumina in the raw material bauxite, adding hydrochloric acid, excess sodium hydroxide, and carbon dioxide to the bauxite solution, and undergoing a chemical reaction Finally, the resulting mixture is filtered twice, then burned, and then carbon is added for high-temperature reduction reaction. On this basis, the existing pouring method is used for smelting, that is, the combination of chemical and physical methods is used to produce high-quality casting. ferrosilicon. Further enhance the strength and toughness of the product. At the same time, it can reduce power consumption by more than 15%, and shorten the smelting time by more than 1 hour, so as to achieve the effect of energy saving and consumption reduction. In addition, the addition of silicon and titanium elements in the production process can accelerate the melting speed of materials and reduce the smelting time. At the same time, it can modify the low ferrosilicon for casting.