相指标分析中黄铁矿中铁的直接测定

DIRECT MEASUREMENTS OF FERRO FROM PYRITE IN FACIES ANALYSIS

一般从测定硫(全硫与硫酸盐硫差值)着手换算黄铁矿中铁。这样没有考虑岩石中自然硫、有机硫和其他形式硫化物存在的影响,且操作烦琐、劳动强度大、成本高。若岩石中有较多的盐酸不溶或难溶硫酸盐(如重晶石、明矾石、石膏等)时,则测定更加困难。为此,我们从铁着手,进行了直接测定黄铁矿中铁的试验。 本法采用1:1盐酸和1:1磷酸的混和酸分离可溶铁(Fe_2O_3);残渣以1:1硝酸溶解测定黄铁矿中铁(FeOFes_2)的含量。

The ferrous content is used to be converted from the sulfur determination (the difference between total sulphur and sulphate - sulphur ) . Therefore , the influence of natural sulphur, organic sulphur and other forms of sulphied matters existing in the rocks are not taken into consideration. Besides the whole process is a complicated operation needing a lot of time,costs and overlaborate procedures. Should there be considerable indissoluble or indissovable sulphate (such as barite, alumstone,gypysum ) in hydrochloric acid of the rock, the measurements would be even more difficult. For this reason, the experiments of direct measurements on ferro from pyrite are carried out. In the experiments, soluble ferro (Fe2O3) was separated by a mixed acid with l : 1 hydrochloric acid and 1:1 phosphoric acid solutions; and then the residue of which is dissolved with l : l nituic acid, and the ferrous content (FeOFeS2 ) is determined from pyrite.