A dry dehydration and deashing process of coal with full particle size

Abstract

The invention discloses a system and technology for coal whole-grain-grade drying method dewatering and deashing. The system comprises a raw coal preparing and drying part, a separating part, and a medium purifying cycling portion. The technology comprises the following steps that to-be-separated raw coal is subjected to smashing and screening, is divided into products of four grain grades of rough, medium, fine, and extremely fine, and respectively enters a photometric sorting machine, a drying method heavy medium fluidized bed sorting machine, a pulsation / vibration heavy medium fluidized bedsorting machine and an electric separator / magnetism fluidized bed sorting machine to separate clean coal and tailing coal; whether a drying device is started is determined based on feed moisture upper limit and feed moisture condition of separating equipment meanwhile; and the medium solid taken out of the product is removed through a sculping screen, and one part of the medium solid enters a magnetic separator to remove non-magnetic materials, and magnetic clean coal flows back to the sorting machines, and the other part of the medium solid is directly recycled and reused. Simultaneous and efficient separating of coal with different particle sizes of rough, medium, fine, and extremely fine grades is achieved, and the problems that in the existing drying method coal separating field, theseparated products are few, quality of the clean coal is poor, the medium application rate is low, and dust is excessively discharged are solved.

Description

technical field [0001] The present invention relates to the field of coal dry separation, in particular to a coal dry separation system and process, in particular to a coal full-grain dry dehydration and deashing system and process based on dry coal separation equipment. Background technique [0002] Coal is the main energy source in my country, accounting for more than 60% of the primary energy production and consumption structure, and plays an important supporting role in my country's energy strategy. my country's coal has the characteristics of high reserves, high impurities, and poor quality. If the raw coal is directly used without clean sorting and processing, it will cause very serious environmental pollution and waste of resources. Coal preparation is the basis of coal clean utilization technology and the source technology of clean coal technology. For a long time, wet coal separation technology has dominated, but more than 2 / 3 of my country's coal is distributed in...

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Problems solved by technology

For a long time, wet coal separation technology has dominated, but more than 2 / 3 of my country's coal is distributed in arid and water-scarce areas such as Northwest China. It is difficult to adopt the traditional wet separation method that consumes a lot of water, which restricts the cleanliness of coal separation. It is very urgent to carry out research on key technologies of high-efficiency dry coal preparation

[0003] At present, the domestic dry coal preparation equipment has a single function, and the effective separation size is limited. It only has a certain separation effect for the rough separation of raw coal with a full particle size or a specific particle size.

Traditional air dry coal preparation methods (such as wind jigging, wind shaker, etc.) use air as the separation medium, and the difference between the separation density and the medium density is more than 1000 times, the separation efficiency is low, and the applicability is poor; relying on photoelectric technology to identify coal The lower limit of the separation of different components of X-ray and image recognition equipment is high, and it is mainly suitable for large-scale coal gangue; the separation equipment of vibration external force and self-generated medium is mainly used for medium and fine-grained coal gangue, and the separation accuracy Relatively low; the dense medium coal preparation equipment using magnetite powder and coal powder as a mixed binary weight can flexibly adjust the separation density and high separation accuracy, but it is difficult to effectively separate fine-grained coal; relying on magnetic fields, Coal preparation equipment with external force fields such as electric field and vibration field can realize effective separation of fine coal, but the processing capacity is low and the added value of the product is small

In addition, due to the limitations of each dry coal preparation equipment, under the separation process based on the equipment design, there are few sorting products, poor clean coal quality, low medium utilization rate, excessive dust discharge, and moisture in the feed. Large impact and other issues limit the degree of quality improvement and efficient utilization of coal resources dry selection

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