Coarse coal slime classifying system and method

A coarse coal slime classifying method, applied to a coal slime classifying system, wherein, the coal slime classifying system comprises a coal slime bucket, an arc-shaped sieve, a hydraulic classifying cyclone, a coal slime centrifuge, and a coal slime chute,

• wherein the coal slime bucket is connected to a coal slime water incoming pipe;
• the hydraulic classifying cyclone is connected to the arc-shaped sieve and the coal slime bucket;
• the arc-shaped sieve is connected to the coal slime bucket and the coal slime centrifuge;
• and the coal slime centrifuge is connected to the coal slime chute and the coal slime bucket;
• and
• wherein a coal slime pump is connected between the electric valve as well as the pressure transmitter and the coal slime bucket;
• the method comprising:
• collecting coal slime produced in a coal washing production process in the coal slime bucket through the coal slime water incoming pipe;
• pressurizing the coal slime in the coal slime bucket by the coal slime pump, and conveying the coal slime to the hydraulic classifying cyclone through a coal slime pipeline;
• performing accelerated sedimentation on the coal slime by the hydraulic classifying cyclone;
• after the accelerated sedimentation, entering an overflow to a concentration tank through the hydraulic classifying cyclone overflow water pipe, and an underflow to the arc-shaped sieve;
• performing solid-liquid separation on the underflow by the arc-shaped sieve;
• returning separated under-sieve water to the coal slime bucket through an under-sieve water pipeline of the arc-shaped sieve, and entering over-sieve materials to the coal slime centrifuge;
• centrifuging the over-sieve materials by the coal slime centrifuge;
• and
• returning a centrifuged centrifugal liquid after centrifugation to the coal slime bucket through a centrifugal liquid pipeline, and entering a discharged coal to a coal bin through the coal slime chute.