GB/T 35051—2018《选煤厂洗水闭路循环等级》中洗水浓度测定方法的说明

Notes on the process water concentration measuring methods specified in the national standard GB/T 35051—2018《Grade for Closed Process Water Circuit in Coal Preparation》

鉴于洗水浓度是选煤厂洗水闭路循环等级评价的重要指标,以及准确、快速测定洗水浓度对选煤生产的重要性,为给选煤生产中洗水浓度测定提供指导,基于对洗水概念的解读,详细介绍了当前选煤生产中四种常用的洗水浓度测定法,包括MT/T 808—1999《选煤厂技术检查》、MT/T 805—1999《煤矿水中悬浮物的测定方法》规定的两种标准测定方法和采用浓度壶、可见光分光光度计进行测定的两种快速测定方法,并对各测定方法的测定步骤和注意事项进行了详细阐述。分析认为,在评定洗水闭路循环等级时可采用两种标准测定方法;当用于选煤厂内部快速检查时,浓度较高的洗水可采用浓度壶来测定,低浓度洗水则推荐采用可见光分光光度计来测定。

Concentration of process water is an essential indicator for evaluation of grade of closed process water circuit of a coal preparation plant,and accurate and rapid measurement of process water concentration is therefore of vital importance for coal preparation operations.In order to provide an effective instruction for the measurement of concentration of the water,the paper presents a detailed introduction,based on the interpretation of the concept of concentration of process water,to four measuring methods commonly applied currently in coal preparation plants,including the two methods as specified in the industry standards MT/T 808—1999《Coal Preparation Plant Technical Control》and MT/T 805—1999《Determination on the SS of Water in Coal Mines》,and another two rapid measuring methods using respectively concentration pot and visible spectrophotometer.Then a detailed account is made on the measuring procedures of each method and the points requiring attention in operation.Result of analysis shows that for the evaluation of grade of process water of closed circuit,the following two standard methods are recommended;and for in-plant rapid determination:measuring high-density water with concentration pot and low-density water with visible spectrophotometer.