Clean coal for combustion and preparation method thereof

A preparation method of a clean coal for combustion, comprising the following steps:

• (1) dispersing starch in water and uniformly stirring to obtain a starch milk with a concentration of 5-20 g/L;
• and heating the starch milk to 70-100° C. and gelatinizing for 10-60 minutes to obtain a starch gelatinized solution;
• (2) adding a sulfur-fixing agent into the starch gelatinized solution under a condition of controlling a temperature of the starch gelatinized solution at 30-60° C., and centrifuging to remove insoluble substances to obtain the starch gelatinized solution containing the sulfur-fixing agent;
• (3) crushing a coal for combustion, and screening to obtain coal particles;
• and
• (4) conveying the coal particles to a fluidized bed, spraying the starch gelatinized solution containing the sulfur-fixing agent on the coal particles in a suspension state, and drying to obtain coal particles adsorbed with the sulfur-fixing agent and gelatinized starch;
• wherein the sulfur-fixing agent in the step (2) is a soluble sulfur-fixing agent;
• and the soluble sulfur-fixing agent is one or more selected from the group consisting of Ba(OH)2, Ca(HCO3)2 and Mg(HCO3)2;
• and
• in step (2), an amylase is further added, and an addition amount of the amylase is 3-6% of a mass of the starch.