柿竹园矿床大理岩型锡矿石工艺矿物学研究

大理岩型锡矿石产于燕山早、中期千里山花岗岩与中、上泥盆统灰岩的外接触带。矿石呈细脉、网脉浸染状,锡矿物有:锡石、黄锡矿,富钛尼日利亚石、尼日利亚石和木锡矿,脉石矿物绿帘石、石榴石、电气石、萤石、方解石及磁黄铁矿等亦含锡,锡主要呈锡的浊立矿物存在,占总锡量的89.78％,其中锡石锡占总锡量的80.01％,其次有呈类质同象形式存在的锡,在绿帘石、石榴石、电气石等矿物中以Sn~(4+)取代Fe~(3+),这类锡占总量的8.33％。工艺矿物学研究表明,该类锡矿石以“贫”、“细”、“杂”为特征。锡不仅十分分散,而且品位偏低,矿石矿物组合及镶嵌关系复杂、相互包裹,紧密连生;锡矿物粒度微细,粒径一般为0.2～0.01mm,部分为<0.0l～0.002mm,是一种难选的锡矿石类型。通过锡的回收试验,采用选冶联合工艺流程,预测锡的最佳回收率可达50％以上。

TECHNICAL MINERALOGICAL STUDY OF THE MARBLE TYPE TIN ORE IN SHIZHUYUAN DEPOSIT

The marble type tin ore occurs in the outer contact zone between Qianlishan granite of early and middle Yanshanian Period and the limestone of Middle and Upper Devonian System. The ore assumes veinlet, stockwork, and disseminated structure. The tin minerals include cassiterite, stannite, Titanium-rich nigerite, nigerite and wood-tin; the tin-bearing minerals include epidote , garnet, tourmaline, flourite , pyrrhotite and calcite etc. The tin exists mainly in the form of independant tin mineral, which occupays 89.78% of total tin, of which cassiterite takes 80.01% of total tin. Secondary, there is tin in the form of isomorphous replacement, contained in epidote, garnet, tourmaline and other minerals in the form of Sn~(4+) replacing Fe~(3+), which account for 8.33% of total tin. Technical mineralogical study indicates that this type of tin ore is characteristic of "poor", "fine" , "complicated" . The tin is not only scattered in the ore, but also low in grade. The ore mineral assemblages and intergrowth are complicated. The tin mineral is very fine, the grain size ranges from 0.2--0.01mm in general , partially from less than 0.01mm to 0.002mm. So it is a kind of hard-to-dress tin ore. According to the recovery test, the combined flowsheet of mineral dressing and metallurgy being applied,it is predicted that the optimal recovery for tin can reach 50% or more.