Purpose. To obtain high-calorie solid fuel from brown coal by increasing its energy characteristics.
Specifications. Using the developed technology for the enrichment of brown coal, a pilot batch of solid fuel with a total weight of 10 kg was produced with a lower calorific value for the working state of the fuel in the range of 4521.9 – 5282.71 kcal/kg, total moisture for the working state of the fuel – 10.3%, ash content – 17.72 – 22.8%, yield of volatile substances – 37.65 – 44.9% and sulfur 2.48 – 2.9%. The obtained characteristics of solid fuel correspond to the quality indicators of thermal coal of the gas group and an analogue of grade D coal can be used at existing thermal power plants and thermal power plants in Ukraine.
Application area. Mining, metallurgy, energy.
Advantages. The proposed technology makes it possible to optimize energy costs per unit of coal product and obtain solid fuel in the form of solid fuel briquettes. Thermal treatment of brown coal helps to reduce the oxygen and hydrogen content, and therefore the release of volatiles to the level of gas group coal. The inclusion of associated minerals (for example, angular clays) in the extraction of brown coal has made it possible to reduce the opening rate, and therefore the cost of the mined rock mass. Involving carbonaceous clays in the total gross production can further expand the resource base of Dneprobas by 1.5 billion tons, and for the Novo-Dmitrovskoye deposit – about 600 million tons. The technology of enriching brown coal and giving it the properties of gas group hard coal solves the issues of the country’s energy security and reducing the import of hydrocarbons increases the efficiency and investment attractiveness of mining enterprises, and also reduces the burden on the environment during open-pit mining.
Technical and economic effect. Operating costs, taking into account the cost of raw materials for producing enriched brown coal, are at the level of $50/t, which is a competitive price compared to hard coal in Ukraine. Potentially, with the simultaneous operation of the most powerful mining lignite enterprises, Ukraine can annually produce at least 15 million tons of brown coal, and taking into account coal clays, significantly more than 20 million tons/year. Per ton of equivalent fuel, production can be more than 4.7 million tons, which will reduce the projected deficit in the gas group of coal.
Description. The process of crushing ordinary brown coal using two-roll and hammer crushers was used to obtain the required fractional composition. The drying of brown coal and clay coals in a pilot industrial sample of a thermal vacuum dryer showed maximum moisture extraction with acceptable energy consumption indicators. Thermal treatment of dry high-ash brown coals made it possible to significantly improve the consumer performance of the organic part of the fuel while simultaneously increasing the share of the inorganic part. Cascade processing of thermally treated brown coal on electric and magnetic separators made it possible to obtain a concentrate with an ash content of 17.72 to 22.8%, a volatile yield of ≤ 35%, and a higher calorific value from 7256.1 to 7523.6 kcal/kg. The obtained and systematized parameters for the processing and enrichment of brown coal can serve as the basis for the manufacture of an industrial production line.