Method for preparing fine water coal slurry by utilizing coal slime in coal preparation plant

Abstract

The invention relates to a method for preparing fine water coal slurry by utilizing coal slime in a coal preparation plant, solving the problems that a product bin can be easily blocked and unloading and quality accidents can be easily caused after washing cleaned coal is doped in the existing coal slime treatment. The method comprises the following steps of: a, firstly carrying out conventional floatation on the coal slime, and reselecting to further eliminate gangue after the coal slime at the density class of 1.8g / cm<3> is obtained; b, smashing the coal slime subjected to the floatation for 20min until average particle size is 7.26Mum; c, preparing the coal slime into water coal slurry with the concentration of 50g / l, and adding 120kg / t of flocculating agent No.2 for stirring and sorting, thus ultra-clean coal with yield of 82.06% and ash content of 1.94% is sorted; and d, adding naphthalene additive with the dosage of 1.0% to prepare the fine water coal slurry with the concentration of 56.15% and the viscosity of 980-1146mPa.s corresponding to shear rate of 100 / s. With the adoption of the method disclosed by the invention, the ultra-clean coal with the ash content being lower than 3% is sorted, the fine water coal slurry with the concentration being about 57% and the viscosity being about 1000mPa.s is prepared; a coarse crushing link is eliminated, energy consumption is saved; the fine water coal slurry can be taken as a raw material for carbon materials such as a carbon electrode and activated carbon; sulphur content of the ultra-clean coal is reduced; and heavy oil, diesel oil and natural gas can be replaced.

Description

technical field [0001] The invention relates to a method for processing coal slime in a coal preparation plant, in particular to a method for preparing fine coal-water slurry from the coal slime in a coal preparation plant. Background technique [0002] Coal slime is a by-product of coal preparation plants. At present, the coal slime in domestic steam coal preparation plants is basically dehydrated by filter presses or pressurized filters and mixed into clean coal for sale. However, the coal slime has high water content and high ash content. After being added to the washed clean coal, the water content of the clean coal will increase, reduce the calorific value of the clean coal, and affect the quality and sales of clean coal products. It is difficult to evenly mix the clean coal into the clean coal , Agglomerates exist in the washed clean coal, it is easy to cause the blockage of the product warehouse, the phenomenon of freezing wagons in winter is serious, and it is easy t...

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a method for preparing fine coal-water slurry from coal slime in a coal preparation plant in order to solve the problem that the product bin is easily blocked and unloading and quality accidents are easily caused after washing and cleaning coal is added to the existing coal slime treatment.