(1) Gold, silver and bismuth in lead concentrate are valuable elements, and the analysis data should be reported;

(2) Two impurities of MgO and Al2O3 in the concentrate are taken as reference indexes, but not as delivery basis temporarily.

The moisture content in the concentrate shall not be more than 12%. In winter, the moisture content of concentrate is no more than 8%. Foreign inclusions shall not be mixed in the concentrate.

The ore dressing technology of lead concentrates is usually produced by lead ore crushing, ball milling, foam flotation and so on. The lead concentrate is up to the national standard. The main composition of lead concentrate is based on product grade, and the lead content is 40--70%.