Process for producing high calorific value water-coal slurry by utilizing coal or coal gangue and coal gasification process adopting process

Abstract

The invention discloses a process for producing high calorific value water-coal slurry by utilizing coal or coal gangue. The coal or the coal gangue comprises incombustible minerals and combustible containing carbon-hydrogen. The process comprises the following steps: A, wet grinding coal or coal gangue in water until an average particle size of particles is smaller than 500 micrometes, adding additives in a continuous wet grinding process, uniformly dispersing the additives, and obtaining micro-nano water-coal slurry; B, introducing micro-bubbles with a diameter smaller than 200 micrometers into the micro-nano water-coal slurry, wherein the mineral particles bonded with the additives are agglomerated and sunken as a bottom stream, wherein the combustible particles containing the carbon-hydrogen floats along with the bubbles to be a floating stream, so that the separation of the mineral particles and the combustible particles can be realized; and C, separating the combustible particles containing the carbon-hydrogen from the floating stream, and preparing the high calorific value water-coal slurry with a calorific value higher than 4000kcal / kg by virtue of press filtering. The invention also discloses a coal gasification process comprising the high calorific value water-coal slurry preparation process, so that inferior coal can be used for gasifying the water-coal slurry at first.

Description

technical field [0001] The invention belongs to the field of coal gasification technology, and in particular relates to a method for producing high calorific value coal-water slurry and by-product mineral compound fertilizer by utilizing coal or coal gangue. Background technique [0002] In the traditional coal gasification process, according to the different raw materials used in the gasifier, it is divided into dry coal gasification process and coal water slurry coal gasification process. The former directly carries dry coal powder into the gasifier with compressed gas for gasification , and the latter usually mix pulverized coal and water into a coal-water slurry and then enter the gasifier for gasification. Because the wet coal gasification process is superior to the dry coal gasification process in terms of feed continuity, stability, and cost, the former has more application prospects in industry. In fact, coal-water slurry gasification has been widely used. Almost a...

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Problems solved by technology

Usually these mineral residues are only suitable for use as the lowest raw materials for brick or cement making or road paving, but if there is no brick or cement factory near the gasification plant, the high transportation cost makes it practically unusable

It has also been proposed to use these mineral residues as soil fertilizers or soil improvers, but the problem is that these mineral residues have been fully sintered or even vitrified after passing through the high-temperature environment in the gasifier, and the useful minerals in them are trace amounts Elements are difficult to release under natural conditions, so they are difficult to be absorbed by plant roots, and their effect as fertilizer or soil conditioner is very limited

Based on various factors, these mineral residues produced by coal gasification plants can only be discarded and have no other use, which not only causes environmental pollution but also cannot recover economic value from them.

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