矿石中钨的重量法测定较繁.络合滴定直接法测钨尚不够完善.间接法测定钨是将试液中钨酸根以钙盐、钡盐或铅盐形式析出,然后用EDTA滴定钙、钡或铅,其中以测定后者的结果较好.以化学法指示络合滴定的终点常因金属指示剂选择或滴定条件控制不当,滴定达终点时指示剂变色往往不够清晰,影响滴定精确度.络合滴定可采用安培法(电流滴定)指示终点. Determination of heavy tungsten in ore method is more complex.Measurement of tungsten by complexometric titration is still not perfect.Indirect determination of tungsten is the test solution of tungstate to calcium salt, barium salt or lead salt precipitation, and then titration with EDTA calcium, Barium or lead, of which the latter to determine the results of the better.Chemical method indicates the end of complex titration often due to metal indicator selection or titration conditions are not properly controlled, titration of the end point indicator discoloration is often not clear enough, the impact of titration accuracy Complex titration can be amps method (current titration) to indicate the end.