Yarm Qieh silica deposit, Khoy
15 Km away from the north of Khoy, there is a silica deposit. Selective sampling from the area shows that it has more than 95% silica and between 0.1 and 0.09% ferric oxide that is suitable for glass making. At 1990, through a contract, the Madankav Consulting Engineers started a preliminary exploration project on this deposit. The deposit has occurred in the Permian rocks that metamorphosed due to granitic intrusion. In order to identify the deposit and contact between the granite and silica and limestone, six trenches were excavated in west and south of deposit. A 100*200 m network was designed for sampling from the silica. Due to cold snowy winter, the sampling was done only from eight locations. These samples have 82.50 to 90.77% silica, 3.7 to 5.99% alumina, 0.48 to 1.57% ferric oxide. Ordinary the increase of silica content is associated with decrease of ferric oxide. Estimated silica reserve is 2.7 million of tons. The available minerals include quartz, muscovite, pyrite, hematite, goethite, feldspar, clay minerals, chlorite, tourmaline, calcite, sphene, zircon, and apatite. The size of minerals ranges between 2 and 50 microns. Fe-bearing minerals sometimes scatter in the silica matrix. Specific weight of ore deposit is 2.65. It has high strength in crushing process; however the relatively coarse grins (500-600 microns) broke from the cementation locus. The processes of gravimetry, magnetic separation, flotation in acidic and basic environments, magnetic flotation and dissolution in acid, didnít lead to a free-iron product acceptable for glass industries.
The product can be used in color glasses, silica sand and fiberglass production. The deposit is recommended for further studies.