阅读说明：本技术 一种全油焦冶炼金属硅的生产工艺 (Production process for smelting metal silicon by using full oil coke ) 是由 段西京 于 2020-03-31 设计创作，主要内容包括：本发明公开了一种全油焦冶炼金属硅的生产工艺,具体按照以下步骤实施：步骤1,对硅石进行水洗；步骤2,以石油焦为还原剂,将石油焦与硅石混合加入电炉中进行冶炼,得到高品质金属硅,其中硅石与石油焦的质量比为2-2.2：1。通过该全油焦冶炼金属硅的生产工艺,可以制备得到高品质的金属硅。(The invention discloses a production process for smelting metal silicon by using full oil coke, which is implemented by the following steps: step 1, washing silica with water; step 2, mixing petroleum coke serving as a reducing agent with silica and adding the mixture into an electric furnace for smelting to obtain high-quality metal silicon, wherein the mass ratio of the silica to the petroleum coke is (2-2.2): 1. by the production process for smelting the metal silicon by the full oil coke, high-quality metal silicon can be prepared.)

1. The production process for smelting metal silicon by using the whole oil coke is characterized by comprising the following steps:

step 1, washing silica with water;

step 2, mixing petroleum coke serving as a reducing agent with silica and adding the mixture into an electric furnace for smelting to obtain high-quality metal silicon, wherein the mass ratio of the silica to the petroleum coke is (2-2.2): 1.

2. the process for producing all-oil coke metallurgical grade silicon metal according to claim 1, wherein in the step 1, the silica has a particle size of 60mm to 100 mm.

3. The production process for smelting metal silicon by using the whole oil coke as claimed in claim 1, wherein in the step 1, the components of the silicon after washing are as follows: si0₂＞99.0％,Al₂0₃＜0.3％,Fe₂0₃＜0.15％,CaO<O.2%, MgO less than 0.15%, and the total content of other impurities is not more than 0.6%.

4. The production process for smelting metallic silicon by using the whole oil coke as claimed in claim 1, wherein in the step 2, a loosening agent is further added during smelting, and the mass ratio of the silica to the loosening agent is 1: 0.4.

5. The process for producing silicon metal from whole oil coke according to claim 1, wherein the loosening agent is wood chips or corn cobs or pressed straws or pressed bagasse or pine cones.

6. The production process for smelting metallic silicon from whole oil coke according to claim 1, wherein the electric furnace is a rotary electric furnace.

7. The process for producing all-oil coke smelted metallic silicon according to claim 6, wherein the electric furnace rotates continuously at a constant speed at a frequency of 15 Hz.

8. The process for producing silicon metal from whole oil coke according to claim 7, wherein in the step 2, the furnace is rammed every 50-60 min during smelting.

9. The production process for smelting metallic silicon by using the whole oil coke as claimed in claim 8, wherein in the step 2, the smelting is performed once every 2.5-3 h.

10. The process for producing all-oil coke smelted metallic silicon according to claim 9, wherein in the step 2, the capacity of the electric furnace is 25500 kVA.

Technical Field

The invention discloses the technical field of smelting processes, and relates to a production process for smelting metal silicon by using full oil coke.

Background

Silicon is an important petrochemical substitute material, energy source material, and electronic material. The earth crust abundance of silicon is 27%, which is second only to oxygen (46%), and is about 1000 times of that of carbon, and the resource is extremely rich, and the development potential is huge. The silicon resource is utilized in large scale and low cost to produce energy and materials needed by human society, and thus the threat brought by the crisis of fossil raw materials is responded, the carbon emission and the greenhouse effect are reduced, and the method is a necessary way for the human society to lead to the future.

Metal silicon (also called industrial silicon) is the most basic functional material of information, new energy and new material industries, is an extremely important upstream product in the silicon product industry chain, is an industrial product derived based on the metal silicon, has various varieties and wide related fields, and is known as magic metal and industrial product essence. The main application is as follows: (1) the additive is used as an additive for smelting aluminum and steel so as to improve the product performance; (2) the method is used for synthesizing various organic silicon materials, preparing various polymers and further processing the polymers into organic silicon. The variety of the global organosilicon material is over 10000, and the global organosilicon material is widely applied to the fields of textile, electronic and electric appliances, petroleum, chemical industry, light industry, building, metallurgy, machinery, military industry, office equipment, transportation, medicine, food processing, daily chemical industry and the like; (3) producing and purifying to produce electronic grade high-purity metal silicon and solar grade high-purity metal silicon which are used for producing various electronic devices such as transistors, rectifier diodes, integrated circuits, electronic computer chips and solar cells; (4) the method is used for manufacturing new materials such as semiconductors, silicon ceramics, silicon carbide, silicon nitride and the like.

At present, domestic electric furnaces for smelting metal silicon (also called industrial silicon) mostly adopt a full-coal production process, but because coal has high impurity content, smelted products are poor in quality and mostly are metallurgical-grade products, and the requirements of photovoltaic industry on chemical-grade metal silicon cannot be met, so that how to produce chemical-grade metal silicon products by adopting one process is a research subject which must be faced by workers in the metal silicon industry.

Disclosure of Invention

The invention aims to provide a production process for smelting metal silicon by using full oil coke, which aims to solve the problem of low product quality in domestic smelting of metal silicon at present.

In order to achieve the purpose, the invention adopts the technical scheme that: a production process for smelting metal silicon by using full oil coke is implemented according to the following steps:

step 1, washing silica with water;

step 2, mixing petroleum coke serving as a reducing agent with silica and adding the mixture into an electric furnace for smelting to obtain high-quality metal silicon, wherein the mass ratio of the silica to the petroleum coke is (2-2.2): 1.

the technical scheme of the invention also has the following characteristics:

in the step 1, the silica has a particle size of 60mm to 100 mm.

In the step 1, after the silica is washed with water, the following components are required: si0₂＞99.0％,Al₂0₃＜0.3％,Fe₂0₃＜0.15％,CaO<O.2%, MgO less than 0.15%, and the total content of other impurities is not more than 0.6%.

In the step 2, a loosening agent is also added during smelting, and the mass ratio of the silica to the loosening agent is 1: 0.4.

The loosening agent is wood chips or corncobs or pressed straws or pressed bagasse or pinecones.

The electric furnace is a rotary electric furnace.

The electric furnace rotates continuously at a constant speed at a frequency of 15 Hz.

In the step 2, the furnace is pounded once every 50-60 min when smelting is carried out.

In the step 2, tapping is carried out every 2.5-3 h during smelting.

In said step 2, the capacity of the electric furnace is 25500 kVA.

The invention has the beneficial effects that: according to the production process for smelting metal silicon by using the whole oil coke, the petroleum coke is used as a single reducing agent, other reducing agents such as bituminous coal and charcoal are not added, and a certain amount of loosening agent (the loosening agent can be wood chips, corncobs and the like) is added, so that the product quality can be further improved; the production process is carried out on the submerged arc furnace with the capacity of 25500kVA or below, the reaction temperature is 2000 ℃, and the consumption of each ton of products is as follows: 2.7t/t of silica, 1.25-1.35t/t of petroleum coke and 0.4t/t of bulking agent, and the obtained high-quality silicon metal (Si is more than or equal to 99.37 percent, Fe is less than or equal to 0.3 percent, Al is less than or equal to 0.3 percent and Ca is less than or equal to 0.03 percent) accounts for more than 95 percent of the total yield.

Detailed Description

The invention relates to a production process for smelting metal silicon by using full oil coke, which is implemented by the following steps:

step 1, washing silica with water; the silica with the particle size of 60mm-100mm is selected, and the components of the silica are required to be as follows: si0₂＞99.0％,Al₂0₃＜0.3％,Fe₂0₃＜0.15％,CaO<O.2%, MgO less than 0.15%, and the total content of other impurities is not more than 0.6%.

Step 2, mixing petroleum coke serving as a reducing agent with silica and adding the mixture into an electric furnace for smelting to obtain high-quality metal silicon, wherein the mass ratio of the silica to the petroleum coke is (2-2.2): 1; when smelting is carried out, a loosening agent is also added, the loosening agent is wood chips or corn cobs or pressed straws or pressed bagasse or turpentine, and the mass ratio of silica to the loosening agent is 1: 0.4.

According to the production process for smelting metal silicon by using the whole oil coke, the petroleum coke is used as a single reducing agent, other reducing agents such as bituminous coal and charcoal are not added, and a certain amount of loosening agent (the loosening agent can be wood chips, corncobs and the like) is added, so that the product quality can be further improved; the production process is carried out on the submerged arc furnace with the capacity of 25500kVA or below, the reaction temperature is 2000 ℃, and the consumption of each ton of products is as follows: 2.7t/t of silica, 1.25-1.35t/t of petroleum coke and 0.4t/t of bulking agent, and the obtained high-quality silicon metal (Si is more than or equal to 99.37 percent, Fe is less than or equal to 0.3 percent, Al is less than or equal to 0.3 percent and Ca is less than or equal to 0.03 percent) accounts for more than 95 percent of the total yield.

Because the photovoltaic industry has strict limits on the content of chemical elements such as iron, aluminum, calcium, titanium, phosphorus, boron and the like in metal silicon (also called industrial silicon) products, the requirements on raw materials are also very strict, and the requirements are that silica is required, wherein Si02 is more than 99.0 percent, Al203 is less than 0.3 percent, Fe203 is less than 0.15 percent, CaO is less than O.2 percent, MgO is less than 0.15 percent, and the sum of other impurities is not more than 0.6 percent; the particle size also varies depending on the capacity of the furnace.

At the same time, attention is paid to the antiknock property of silica, and an appropriate particle size is selected for the antiknock property. In order to ensure good blast resistance, the silica selected according to the invention has a particle size of 60mm to 100 mm.

The main reducing agents used for smelting chemical grade metallic silicon (also called industrial silicon) are petroleum coke, bituminous coal and charcoal. In order to increase the resistivity and chemical activity of the furnace charge, gas coke, silica coke, blue carbon, semicoke, low-temperature coke and wood blocks are also arranged. Among the carbonaceous reductant chemicals, fixed carbon, ash, volatiles and moisture should be considered primarily. Generally, the fixed carbon is required to be high, and the total amount of the required reducing agent is reduced, so that the impurities brought by ash are less, the slag amount is correspondingly reduced, the electric energy consumption is reduced, and the impurity content in the chemical silicon is reduced. The carbonaceous reducing agent has a high specific resistance and a high porosity. The charge resistivity depends mainly on the carbonaceous reducing agent. The carbonaceous reducing agent has large resistivity, good chemical activity and high silicon recovery rate.

The petroleum coke is the lowest ash content in the reducing agent used for producing the metallic silicon (also called industrial silicon), and comprises 0.17-0.6% of ash content, 90-95% of fixed carbon and no more than 3.5-13% of volatile components. The technical scheme of the invention adopts petroleum coke as a reducing agent because of low ash content, which is beneficial to improving the product quality.