What is Manganese Silicon?

What is Manganese Silicon?

Manganese silicon is an alloy composed of manganese, silicon, iron and some carbon. The manganese content in manganese silicon is generally between 40% and 50%, and the silicon content is between 15% and 30%. This alloy has high hardness, high melting point and excellent heat resistance, and is widely used in steel smelting, casting and power industry.

Manganese silicon plays an important role in steel production. Adding an appropriate amount of manganese silicon can improve the hardness, toughness and wear resistance of steel, and can also effectively inhibit bubbles and inclusions in steel, and improve the strength and ductility of steel. In addition, manganese silicon can also increase the thermal stability of steel, improve its oxidation resistance and heat resistance, and make steel more suitable for applications in high temperature environments.

Silicon manganese alloy:

(1) Concept: Silicon manganese alloy is an alloy composed of manganese, silicon, iron and a small amount of carbon and other elements. It is an iron alloy with a wide range of uses and a large output. Silicon manganese alloy is a commonly used composite deoxidizer in steelmaking, and is also a reducing agent for low-carbon ferromanganese and electric silicon thermal method to produce metallic manganese in production. Silicon manganese alloy can be smelted in large, medium and small submerged arc furnaces in a continuous operation.

(2) Silicon manganese is more common in the southwest of China, including Yunnan, Guizhou, Guangxi and Hunan. The raw materials for producing silicon manganese alloy include manganese ore, manganese-rich slag, silica, coke, etc.

(3) Common grades: FeMn68Si18 FeMn65Si17 FeMn60Si14

(4) Raw materials: manganese ore, manganese-rich slag, coke, silica, lime, etc.

1. Uses of silicon manganese alloy:

Silicon manganese alloy is mainly used as an intermediate material for deoxidizer and alloying agent in steel production, and is also the main raw material for medium and low carbon ferromanganese production

2. Production method of silicon manganese alloy:

Silicon manganese alloy is produced by using carbon to simultaneously reduce the oxide and silicon dioxide in manganese ore (including manganese-rich slag) and silica in a silicon manganese alloy submerged arc furnace.

3. Properties of silicon manganese alloy:

Blocky, silvery, specific gravity 6.0-6.4

Manganese ore:

The reserves are mainly concentrated in South Africa, Mozambique, Australia, Russia, Myanmar, Gabon and other countries. my country's manganese ore production areas are Liaoning, Hunan, Sichuan, Guangxi and other regions, but because of the low grade, a large amount of high-grade manganese ore needs to be imported from abroad every year for use.

The grade of furnace manganese ore should be above 30%. Domestic manganese ore is poor, and some rich manganese ore (greater than 30%) needs to be imported mainly from Brazil, Gabon, Australia and other countries. According to incomplete statistics, for every 1% decrease in manganese ore grade, the power consumption of silicon-manganese alloy increases by 135KWh. Increasing the grade of manganese ore entering the furnace as much as possible is an important means to increase manganese recovery rate, reduce power consumption, and improve other indicators.

Requirements for silica: SiO2>97%, P2O5<0.02%, particle size 10-40mm, without soil and debris.

Requirements for coke: fixed carbon>84%, ash content<14%, coke particle size, generally 3-13mm for small and medium-sized electric furnaces, and 5-25mm for large electric furnaces.

Manganese silicon alloy is divided into 8 grades according to the different contents of manganese, silicon and their impurities. The chemical composition is as follows:

Grade Chemical Composition/%

Mn Si C P S

ⅠⅡⅢ

≤

FeMn64Si27 60.0～67.0 25.0～28.0 0.5 0.10 0.15 0.25 0.04

FeMn67Si23 63.0～70.0 22.0～25.0 0.7 0.10 0.15 0.25 0.04

FeMn68Si22 65.0～72.0 20.0～23.0 1.2 0.10 0.15 0.25 0.04

FeMn64Si23 60.0～67.0 20.0～25.0 1.2 0.10 0.15 0.25 0.04 FeMn68Si18 65.0～72.0 17.0～22.0 1.8 0.10 0.15 0.25 0.04 FeMn64Si18 60.0～67.0 17.0～20.0 1.8 0.10 0.15 0.25 0.04 FeMn68Si16 65.0～72.0 14.0～17.0 2.5 0.10 0.15 0.25 0.04 FeMn64Si16 60.0～67.0 14.0～17.0 2.5 0.20 0.25 0.30 0.05

Mn: Manganese

Si: Silicon

C: Carbon

P: Phosphorus

S: Sulfur

The approximate consumption of smelting one ton of manganese silicon alloy is:

Manganese ore (containing Mn28.5%) 2000~2100kg

Manganese-rich slag (containing Mn36%) 700~800kg

Silica 250~280kg

Coke 550~650kg

Power consumption 4500~4800KWh/t

Manganese recovery rate 75%~80%

Silicon recovery rate 40%~50%