Raw materials for the electrode industry. Main types of raw materials

The formation of the electrode industry,the maintenance and expansion of this industry are possible only in advanced economies. The first states that created this sector were Germany, the United States, and Japan. After them, the production of electrodes began in the USSR.

Importance of industry

The production of electrodes is onefrom the most important economic sectors. It ensures the economic independence of the state. The electrode industry acts as an integral part of the heavy industry - ferrous and non-ferrous metallurgy, aviation, mechanical engineering, electrical engineering and electronics, nuclear energy and many other industries. In this case, it is worth mentioning Japan as an example. During the crisis, this country, eliminating the production of aluminum, redirected resources to preserve and develop the electrode industry. As a result, more than 100 enterprises of this industry operate in the country today. Domestic manufacturers, despite the significant difficulties associated with reducing the consumption of products, continue to be in the lead among the CIS countries. Currently, the market has created quite a tough competition between foreign and Russian manufacturers. In these conditions, the first place is put forward by two main circumstances. First of all, the cost of production is important. It, in turn, affects the allowable minimum selling price. The second circumstance is the quality that electrodes for welding, blocks for furnaces, structural graphites and other products possess. In this case, it is about what the specific results of their use are - what is the specific consumption, how many will the products serve.

The main component of cost and quality

The formation of these indicators affects the set offactors. Among them are the costs of transport, materials, technological fuel, labor, electricity and so on. All these costs account for more than 80% of the cost of production. Raw materials for the electrode industry is one of the most important factors. It affects not only the cost price, but also the quality of products. In this regard, the raw material base of the industry acts as one of the indicators of economic and technical competitiveness.

Structure of consumption of materials

It is determined in accordance with the main nomenclature of manufactured products in Russia. In particular, domestic enterprises produce:

Graphitized electrodes for electric arc furnaces.
Carbon graphite cathode blocks.
Electrodes and weights for the production of silicon and aluminum.
Structural graphites for various industries.
Electrodes for arc welding and so on.

Main types of raw materials

Domestic enterprises use different materials. The most common are:

Petroleum coke. It can be special or ordinary quality.
Shale coke and needle structure.
Technological anthracites.
Coal pitch.

Difficulties with materials

Today in Russia there are no enterprises,producing low-sulfur petroleum coke. About 200 thousand tons of raw material was outside the country in Turkmenistan, where its release for certain reasons was reduced. For today, the actual option is the creation of hydrotreating units for coking feedstocks in oil refineries. This will allow to organize the release of a material with a reduced sulfur content in the Russian territory. But the implementation of projects for deep oil refining and the necessary reconstruction of many refineries suggest a reduction in the volume of coking feedstock. The material of the needle structure is purchased mainly abroad. The main suppliers are the USA and Japan. This raw material for the electrode industry produced and domestic Novoufimsky refinery. This enterprise has shown real possibilities both for the required volume and for the required quality of products. First, experimental, and then industrial batches of material were produced. The volume of output left 1.5 thousand tons. Today, it depends on the regularity of supply of low-sulfur deficit oil. Some enterprises show fairly stable results in the production of materials. Thus, in recent years, the quality of coal tar has stabilized to a certain extent. However, not all of the involved companies have established production of "A" and "B" brands. It is this raw material for the electrode industry that has a special significance, which is reflected in the number of orders for it. There is no stability in the release of other important materials. For example, this applies to pyrolysis pitches, which can act as an additive to coal tar. In separate technological operations, these components are extremely necessary. There is no release of high-temperature coal pitch (grade "T"). It is necessary for obtaining some structural materials of the carbon type.

State of domestic enterprises

Reduction of attention to the problem of supply of raw materials forelectrode industry caused a shortage of carbonaceous material and an increase in the volume of imports - from 35 to 100%. Thus, the untimely preparation of the sections and quarries of the Kolyvan Technological Anthracite Deposit located in the Novosibirsk Region, and the delay in overburden for more than 5 years, caused a sharp decline in the extraction and enrichment of this raw material. Significant changes have occurred in the supply of materials for the production of structural graphites. In connection with the cessation of the production of pyrolysis coke in 1992-94, their volume has sharply decreased. The acute problem of searching for alternative materials, which arose, required an immediate solution. Moscow electrode factory, and after him and the NEZ (Novocherkassk enterprise), began research and work on the development of technology for the production of structural graphites. For this, cooperation was established with the Slate-Chemical Combine in Estonia.

Achievements of Russian enterprises

Chelyabinsk Electrode Plant subsequently alsoengaged in similar work. As a result of the research, new lines were launched at the enterprise. As a result, ChEZ produced lots of various grades of structural graphite based on pitch coke. Material for them is supplied by domestic enterprises. The characteristics of the graphites obtained correspond to those prepared using petroleum coke. Thus, the task of supplying different brands of material for a wide range of purposes was solved. In addition, the production and dispatch to the nuclear power plants of products from structural graphites, necessary for the construction and repair of RBMK units, was restored. To complete the development of pitch coke, acting as a filler in structural graphites, it is necessary to perform certain technological and technical measures in the process of its preparation and preparation.

Characteristics of materials

In the production of all types of carbon-graphite raw materialsnatural and artificial components are used. The main component in them is carbon. Natural materials include natural graphites and anthracites. Artificial components, however, make up the bulk of the carbonaceous raw materials. Different forms of the main ingredient of the raw material are obtained by decomposition of organic compounds. They can be formed from the liquid or gas phase. Also, their production is possible when decomposing solid compounds. From the gas phase, for example, certain types of soot are formed, of liquid, in turn, oil cokes. The raw material and processing method have a decisive influence on the characteristics of the final product.

All raw materials for the electrode industry can be divided into 2 groups: solid carbon components and binders. Consider them.

Solid materials

1. Anthracite. It acts as the main component of coal blocks and electrodes used in the laying and lining of bathtubs, ovens, etc. The main requirements for anthracite are:

Low sulfur content.
Thermal resistance.
Low ash content.
Mechanical strength.
High electrical conductivity.

The use of anthracite in compositions improves the performance characteristics of products, primarily their thermal conductivity.

2. Coke. This is one of the most important components for the electric and electronic industry. Today, two types of this material are produced. The first - oil - is obtained by coking oil residues. Its properties depend on the type of source material. Production of this type is carried out in 2 ways. In accordance with the first, coking is carried out in heated metal cubes. The second method is a slow process in unheated cells. The second type is obtained by processing coal tar pitch.

Graphite

This component is used in mostcarbon graphite materials. When graphite is introduced into the mass, its plasticity improves, internal and external friction decreases. This allows obtaining more dense welding electrodes and other products. Even a small amount of graphite (4-6%) positively affects the properties of the product. In particular, its heat resistance, thermal and electrical conductivity is increased. The main parameters determining the quality of graphite grades are granulometric composition and ash content. However, they are sufficient only when it comes to the material of a particular deposit and the method of production. With the same value of indicators graphs of different origin may have differences in other properties.

Technological process

The slowed-down method of obtaining coke todayis considered the most popular. The essence of this process is that the material, preheated to 500 degrees, is pumped into insulated non-heated reactors outside. According to various schemes, from 2 to 4 reactors can be installed in the unit. The temperature in them is 470-480 degrees, and the pressure is up to 1.7 atm. The unit is designed for filling in a day. After it is turned off, the filled reactor is steamed. This is necessary for distilling oil from distillate fractions. They, in turn, are sent to the distillation column.