RU2214446C2 - Method of preparing coal-water fuel from coal slack - Google Patents

Abstract

FIELD: alternative fuels. SUBSTANCE: single-step preparation of coal-water fuel includes preliminary wet crushing of coal slacks and hydromining waste, their classification, and introducing solids with particle size up to 1 mm, water, and reagent into horizontal vibratory-wave tore mixer-homogenizer with vertical driven element amplitude 1-4 mm, horizontal driven element amplitude 1-6 mm, and rotation speed 1400-2000 rpm. EFFECT: reduced power consumption: no more than 15 kW per 1 t coal-water fuel. 2 cl, 3 ex

Description

 The invention relates to methods for the preparation of water-coal fuel (HLF) for its subsequent combustion and can be used in the coal industry and energy.

 A known method for the preparation of HLW by preliminary grinding of coal waste and coal slurry by preliminary wet grinding with their subsequent classification and feeding of solid particles, water and reagent into the mill for further grinding to produce fuel containing more than 70% solid particles containing 5-6% of particles with a diameter less than 1 micron and 3-5% of particles with a diameter of more than 200 microns (French Application 2595712, C 10 L 1/32, 09/18/08).

 Closer to this invention, in essence, is a method for the preparation of HLW by preliminary coarse grinding of solid fuel (any, including waste water and coal sludge) in the presence of water, followed by their classification and feeding the classified solid particles, water and dispersing agent into a mill filled with fragments ball obtained using 6 dissecting planes for mixing and homogenization. The coal particles entering the mill are less than 3 mm in size. Trimming balls have a diameter of 23-25 mm (Japanese Application 63-17991, C 10 L 1/32, publ. 25.01.88).

 A disadvantage of the known methods are the significant energy costs for the production of HLW.

 The aim of this invention is to reduce energy consumption for the production of HLF.

 This goal is achieved by a single-stage preparation of HFM, including coarse wet grinding of coal sludge and waste water, their classification and the supply of classified solid particles with a size of not more than 1 mm, water and reagent into a horizontal vibration-wave torus mixer-homogenizer with amplitudes of the vertical working body 1-4 mm, and horizontal working body 1-6 mm. The frequency of rotation of the working body should be equal to 1400-2000 rpm

 It is desirable to carry out the process in the mixer homogenizer with a mass of grinding media up to 2000 kg and a diameter of 10 to 40 mm.

 This method allows you to spend on the production of 1 ton of HLW not more than 15 kW of electricity.

 The following are examples illustrating the achievement of the goal.

Example 1
The feedstock is coal slurry from brand G coal (ash content of 23.1%, maximum humidity - 28.5%, sulfur content - 0.6%, volatiles yield - up to 42.4%, calorific value - 5180 kcal / kg, having the following particle size distribution: class 1-3 mm - 11.8%, ash content 29.1%; class 0-1 mm - 88.2%, ash content 21.3%) from a coal warehouse is fed by a conveyor belt to a plow ejector and then it enters the receiving hopper, where it is diluted with water to a moisture content of 55%. After that, the screw is fed into the crusher, where coal particles of a class up to 3 mm are crushed, and a particle class up to 0.5 mm passes through a vibrating sifter and enters the storage hopper. From the hopper through a vibrating weighing batcher, the calibrated coal slurry is supplied together with a plasticizer (1 wt.% For coal) to a vibration-wave torus mixer-homogenizer. The homogenizing mixer had a spherical loading of grinding bodies: 10 mm - 150 kg; 23 mm - 850 kg; 30 mm - 600 kg; 40 mm - 250 kg.

 The mode of operation of the mixer-homogenizer: rotation speed - 1800 rpm; the oscillation amplitude is vertical 3 mm, horizontal 4.5 mm. The loading of coal slurry with a humidity of 46% and the unloading of the finished HLW were carried out continuously in an amount of 100 kg / min. A stable coal-water fuel with an average particle size of coal sludge of 28.5 μm was obtained. Energy consumption per 1 ton of fuel-and-chemical fuel amounted to 15 kW.

Example 2
The carbon slurries of the composition shown in Example 1 were preliminarily prepared as in Example 1 and then fed together with a plasticizer (1.5% on coal) into a vibration-wave torus mixer-homogenizer with an oscillation amplitude of a vertical working body of 1 mm, horizontal 6 mm. The frequency of rotation of the working body 2000 rpm The homogenizing mixer had a load of grinding bodies of 2000 kg. Received water-coal fuel with an average particle size of 25.2 μm, and containing 55% of solid particles. Energy consumption per 1 fuel and energy complex amounted to 14.2 kW.

Example 3
The coal slurry of the composition shown in example 1 was preliminarily prepared as in example 1.

 After preliminary preparation, the sludge together with a plasticizer (1 wt.% On coal) was fed into a vibration-wave torus mixer with a homogenizer with an oscillation amplitude of a vertical working body of 4 mm and a horizontal working body of 1 mm. The frequency of rotation of the working body 1400 rpm The homogenizer mixer had a working fluid load of 1,500 kg. A fuel was obtained with an average particle size of 28.8 μm and a solid content of 53.5%. Energy consumption per 1 ton of fuel-and-chemical fuel amounted to 14.8 kW.

Claims (2)

 1. A method of preparing water-coal fuel from coal sludge, including preliminary rough wet grinding of coal sludge and waste water, their classification and the supply of classified solid particles, water and a reagent for mixing and homogenizing the mixture, characterized in that the mixing and homogenization is carried out in a horizontal mixer-homogenizer vibration -wave torus with amplitudes of the vertical working body 1-4 mm, horizontal working body 1-6 mm and a rotation frequency of 1400-2000 rpm and the size of the solid particles, feed s in a homomixer, not more than 1 mm.  2. The method according to claim 1, characterized in that the process is conducted in a mixer-homogenizer with a mass of grinding media up to 2000 kg and a diameter of 10-40 mm.