The largest ball mill in the coal chemical industry for the Inner Mongolia Rongxin project completed its single-unit trial run successfully on the first attempt

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The largest ball mill in the coal chemical industry for the Inner Mongolia Rongxin project was successfully tested on its own for the first time. Author/Source: Coal Chemical Industry 114 Forum. Date: 2019-10-08. Clicks: 58. Recently, the largest ball mill in the coal chemical industry for the Hualu Technology Inner Mongolia Rongxin project was successfully tested on its own from the first attempt. The ball mill is one of the core equipment in the gasification unit, responsible for grinding the coal lumps delivered from the coal preparation unit into coal powder. The project features four ball mills of the overflow type, which breaks with the previous practice of using rod mills in the coal chemical industry; this approach improves the fineness of coal powder and extends the service life of the mills. The ball mill drum specifications are φ5.2*8.5m; the motor’s rated power is 3800kW. The loading capacity per mill for steel balls is 252 tons, with a solid concentration of 56.5~65wt%. The density of the coal slurry is 1150~1250kg/m3, and the production rate per mill is 131 t/h (on an air-dry basis). It is the largest ball mill in use in the coal chemical industry to date. Since September, the Rongxin project team has overcome numerous difficulties. Under tight deadlines and heavy workload, and guided by the meeting on advancing the trial production of the Rongxin project at the group company, all team members have demonstrated a spirit of hard work and determination, often working late into the night to ensure that the ball mill could be tested on schedule. During the commissioning phase, a series of preliminary preparations were completed, including ensuring proper oil supply to the ball mill’s oil station, tuning the frequency converters, conducting tests on the slow drive system individually, testing the main motor separately, and testing the reducer individually. The successful trial run of this ball mill lays a solid foundation for establishing the process flow in the gasification unit and starting pilot production in October. The 400,000-ton coal-to-ethylene glycol and 300,000-ton polydimethyl ether production project, which is part of the circular economy initiative carried out by Yanzhou Coal Industry Ordos Energy Chemical Rongxin Chemical Co., Ltd., builds upon the company’s first-phase project for producing 900,000 tons of coal-to-methanol per year. Through further expansion in subsequent phases, the company aims to extend the coal chemical industry chain, ultimately achieving an annual production capacity of 5 million tons of coal-to-methanol as well as a demonstration base for a range of downstream fine chemical products. This initiative seeks to create a new benchmark for coal conversion and industrial upgrading. The project primarily produces 900,000 tons per year of methanol, using the four-nozzle gasification technology developed by East China University of Science and Technology to generate CO and H2 required for the production of ethylene glycol, as well as syngas needed for methanol synthesis. Ethylene glycol is synthesized via an indirect method, and DMMn is produced from methanol through an indirect process. The main construction components of the project include 3 coal gasification units using 4,000 t/d coal slurry gasifiers (with a coal feeding capacity per unit that is the highest among gasifiers in the world today), purification systems (CO conversion, low-temperature methanol washing, deep cryogenic CO separation, PSA hydrogen production), sulfur recovery systems, a methanol production plant with an annual capacity of 900,000 tons, an ethylene glycol production plant with an annual capacity of 400,000 tons, a DMMn production plant with an annual capacity of 300,000 tons, 2 air separation units with a capacity of 92,000 Nm3/h each (the largest of their kind currently), 2 high-pressure circulating fluidized bed boilers with a capacity of 380 t/h each, along with 2 steam turbine generators rated at 20 MW each, as well as various auxiliary and supporting process equipment