Phosphate usually means the ore that could be recovered phosphate mineral, its grade is expressed by P2O5 percentage, as w（P2O5）%. We are the second phosphate mine resource county in the world, and our phosphate is 176million tons, it manly distributed in Yunnan, Guizhou, Sichuan, Hubei and so on. Our phosphate ore distribution is as follows:
|Deposit types||Surrounding rock types||Main mental mineral and gangue mineral||Examples|
|Marine sedimentary phosphate rock deposit||Carbonates, silicates (cherty rock) argillaceous, argillaceous rocks||The main mineral is oil aphanitic carbon fluorapatite (collophane), followed by a carbon apatite and Coors stone. Gangue minerals include dolomite, calcite, quartz, chalcedony, carbonaceous, pyrite||Yuji, Shimen, Yichang, Chaoyang, Haikou, Kunyang, Kaiyang.|
|Sedimentary-metamorphic rock phosphate deposit||Schist, marble, quartzite, gneiss, calcareous biotite, quartz schist, quartz muscovite schist, chlorite schist||Major minerals are fine apatite. Gangue minerals include quartz, calcite, dolomite, mica. Pyrite, limonite, kaolin, biotite, etc.||Jingping, Huangmailing, Jianghuai, Susong|
|Magmatic apatite rock deposit||Gabbro, pyroxenite, dunite, anorthosite, norite||The main minerals are apatite, titanium vanadium magnetite, magnetite and rare earth elements can be comprehensive utilization. Gangue minerals are plagioclase, amphibole fibers, chlorite, pyroxene, epidote, pyrite, etc.||Maying, Gongshan, Jianping|
|Guano phosphorite bed||Carbon rocks||The main minerals are calcium, Monetite, white phosphorus, calcium mineral, brushite, carbon apatite, hydroxyapatite. Gangue minerals include quartz, chert, and carbonate bioclastic||Nansha, Xisha and other island|
Phosphate ore is mainly used in the fertilizer industry, and also can be used in an airline, food, medical and national defense.
Nowadays, we have an increased demand for phosphate, and with the exploration of the phosphate-rich ore, there is less rich ore and more poor ore, it pushes the research and development of mining equipment and technology.
Different components phosphate ore has low hardness and belongs to fragile ores, so crushing and screening stage often uses two stage and one closed process as 1（a） and two-stage open process as 1（b）. Phosphate ore coarse crushing often uses jaw crusher or gyratory crusher, middle size crushing often use cone crusher, screening often uses circular vibrating screen or linear vibrating screen.
2, Grinding stage
Phosphate ore has good grindability, so it always adopts onstage closed grinding or two-stage one close grinding, the grinding equipment is ball mill. The regular ball mill (grid ball mill or overflow ball mill) has higher energy and steel consumption and higher cost. Xinhai manufactures all kind of ball mill which can decrease the energy and steel consumption (about 20%-30%), and xinhai wear-resistant rubber could improve the liner service life and equipment operating rate.
3, Beneficiation stage
Phosphate ore process has scrubbing and dismiling process, gravity separation process, flotation process, gravity-magnetic-flotation process, roasting – digestion process, microbial treatment process, dry electrostatic separation process, magnetic cover craft process. We have use flotation process, gravity separation + flotation process in actual production.
The brief introduction of phosphate ore process:
Advantages: it could process all kind of ore. Positive flotation can remove siliceous gangue, so it can handle and sedimentary-metamorphic siliceous phosphate silicon - calcium phosphate limestone. Single-positive flotation could remove calcium (magnesium) gangue, so it can process sedimentary calcium (magnesium) quality phosphate ore, reverse-positive (positive-negative) flotation process and double flotation process could enrich the phosphate ore by removing silicate minerals and carbonate minerals, so it can handle refractory sedimentary calcium silicon (magnesium) quality phosphate ore. Stage flotation could process gangue minerals and phosphate which has disseminated fine grain size of collophanite. Flotation beneficiation process has good indexes, sulfur concentrate W (P2O5) grade could up to 30% to 40%; phosphorus recovery rate could up to 75% to 90%.
The flotation operation condition and indexes as follows:
|time（min）||concentration（%）||Product gradeβ（%）||Phosphate recovery rateε（%）|
Flotation equipment: the main equipment is flotation cell. Flotation cell has self-absorbed mechanical flotation cell, air-inflation flotation, airlift and depressurized flotation cell. At present, many miners use xinhai flotation. Xinhai manufactures all kinds of flotation, and it has high work efficient, lower maintenance, low consumption, good flotation indexes, and competitive price, it decreases the flotation cost.
Gravity separation + flotation process
Process advantages: it can be widely used in sorting silicon calcium phosphate ore. It has good flotation indexes, phosphate concentrate ore W（P2O5）grade can up to 30%~41%, phosphate recovery rate can up to 75%~90%, gravity separation has less cost and pollution. It can eliminate most tailings, can greatly reduce the use of flotation reagents, flotation device, saving cost.
Gravity separation equipment and flotation equipment:
Heavy media separation equipment mainly has heavy media cyclone and jigger. Flotation equipment is all kinds of flotation cells. Commonly used heavy media is ferrosilicon, magnetite, pyrite, etc. Shandong xinhai mining technology and equipment Inc. manufactures all kinds of diaphragm jig, sawtooth jig, and flotation machines, we can provide all kinds of phosphate ore machines, and make phosphate ore has a good flotation index.