Method for upgrading coal slime through synergistic dehydration

A method for upgrading a coal slime through synergistic dehydration, comprising:

• subjecting coal slime water to be treated to filter pressing dehydration to obtain a filter cake;
• and
• crushing the filter cake, sieving and sizing, and subjecting a resulting oversize to steam transient dehydration to obtain a dehydrated coal slime, wherein:
• the filter pressing dehydration is conducted by using a filter press, and the coal slime water to be treated is sent into the filter press through a feeding pump;
• the crushing is conducted by using a crusher, and the filter cake obtained after the filter pressing dehydration is sent into the crusher through a first belt conveyor;
• the sieving and sizing is conducted by using a sizing sieve, and an undersize obtained after the sieving and sizing is sent into a coal slime bin through a second belt conveyor for recycling;
• the steam transient dehydration is conducted at a saturated steam temperature of 264° C. to 295° C. and a steam pressure of 5 MPa to 8 MPa for not greater than 5 min;
• the steam transient dehydration is conducted in a system comprising a steam dehydration system, a steam generation system, and a steam recovery system;
• the resulting oversize is sent into a dehydration chamber of the steam dehydration system through a third belt conveyor and then the dehydration chamber is sealed;
• saturated steam generated by the steam generation system is introduced into the dehydration chamber of the steam dehydration system, and pressure preservation is conducted after reaching a pressure of the steam transient dehydration;
• after the pressure preservation is completed, the saturated steam is released, and a released saturated steam is introduced into the steam recovery system for recycling;
• and
• the dehydrated coal slime is sent into a product bin through a fourth belt conveyor.