Pipeline transportation method of coal

1. A pipeline transportation method of coal, the method comprises:

pulverizing coal to obtain pulverized coal having a diameter of 500 μm or less;

performing a waterproofing treatment on the pulverized coal; and

transporting the waterproof pulverized coal to a destination, which comprising:

pumping water into a pipeline until a constant flow rate of the water is reached;

adding the waterproof pulverized coal into the pipeline, such that the waterproof pulverized coal can be transported by the water at a uniform rate;

pressurizing a mixture of the waterproof pulverized coal and the water by a shear-free pump, or pressurizing the water only by a centrifugal pump after separating the waterproof pulverized coal from the water and then adding the separated waterproof pulverized coal back to the water;

directing the mixture of the waterproof pulverized coal and the water into a static pool, so that the waterproof pulverized coal can float on the water surface and the water can be discharged;

collecting the waterproof pulverized coal by a cyclone separator via a negative pressure collection method; and

storing the collected waterproof pulverized coal in a warehouse at the destination,

wherein a specific weight of a single particle of the waterproof pulverized coal is less than a specific weight of the water,

wherein a time needed for precipitating the waterproof pulverized coal in water is longer than a time needed for transporting the waterproof pulverized coal to the destination.

2. The pipeline transportation method of claim 1 , wherein the waterproofing treatment is paint spraying, waxing, or chemical treating surfaces of the pulverized coal.

3. The pipeline transportation method of claim 2 , wherein the waxing method comprises:

adding 0.2-20 wt % of paraffin wax or paraffin emulsion to the pulverized coal t form a mixture; and

heating and rolling the mixture to a temperature of at least 80° C. for at least 20 minutes.

4. The pipeline transportation method of claim 2 , wherein the chemical treating method comprises:

adding 5-30 wt % of calcium salt, 0.2-10 wt % stearate or a salt of stearate, 0.2-10 wt % of paraffin wax to the pulverized coal to form a mixture; and

heating and rolling the mixture to a temperature of at least 120° C. for at least 20 minutes at a heating rate of 2° C./min.

5. The pipeline transportation method of claim 4 , wherein the calcium salt comprises CaCO 3 .

6. The pipeline transportation method of claim 4 , wherein a heating rate of the heating step is about 2° C./min.

7. The pipeline transportation method of claim 2 , wherein the chemical treating method comprises:

adding 5-20 wt % of Ca(OH) 2 to the pulverized coal to form a uniform mixture;

adding 1-10 wt % of a solution of a fatty acid ammonium to the mixture; and

drying the mixture.

8. The pipeline transportation method of claim 2 , wherein the chemical treating method comprises:

adding 2-20 wt % water-soluble sodium methylsilanolate and 5-20 wt % of CaCO 3 to the pulverized coal to form a mixture;

stirring the mixture; and

drying the mixture.