煤粉细度测定步骤

Steps for measuring the fineness of coal powder

（1）将底盘、孔径90及200的筛子自下而上一次重叠在一起。

 Overlap the chassis, sieves with apertures of 90 and 200 from bottom to top.

（2）称取煤粉样25g（称准到0.01g），至于孔径为200筛内，盖好筛盖。

Weigh 25g of coal powder sample (accurate to 0.01g), and cover the sieve cover with a pore size of 200.

（3）将上述以叠置好的筛子装入振筛机的支架上

Install the stacked sieve onto the bracket of the vibrating screen machine

（4）振筛10 min ，取下筛子，刷孔径为90筛的筛底一次，装上筛子再振筛5 min。（若再振筛2 min ，筛下煤粉量不超过0.1g时，则认为筛分安全）。实验室手动180次

 Shake the sieve for 10 minutes, remove the sieve, brush the bottom of the 90 sieve once, install the sieve, and shake the sieve for 5 minutes. If the amount of coal powder below the sieve does not exceed 0.1g after another 2 minutes of shaking, it is considered safe for screening. 180 manual tests in the laboratory

（5）取下筛子，分别称量孔径为200及90筛上残留的没分量，称准到0.01 g。用玻璃皿称重。

Remove the sieves and weigh the remaining residue on the 200 and 90 sieves, accurately weighing to 0.01 g. Weigh in a glass dish.

（6）结果计算

result calculation