Study On Regrinding Process And Flotation Rate Of Flake Graphite

The graphite resources of large flake in our country is relatively inadequate. The flake graphite products have the greatest demand and the most widely application in graphite products, besides, their value is proportional to the size and grade. However, due to the damage that traditional grinding-floating process could cause to graphite flake, it is of great significance to select regrinding process reasonably aiming at flake graphite of different disseminated grain size.The research of ore properties, rughing conditions, open-circuit flow and flotation rate were carried out, and the conclusions were as follows:The study about ore properties showed that the carbon content of 1# and 2# respectively were 4.45% and 9.29%. The main gangue mineral of 1# was quartz, followed by feldspars, mica, tremolite and chlorite; the main gangue minerals of 2# were quartz and diopside, followed by feldspars, mica, tremolite, calcite and pyrite. The cumulative ratio of number of graphite particles greater than 0.15 mm were respectively 3.10% and 10%.The experiments of roughing conditions suggested that the better grinding fineness under 0.074 mm of 1# was 66.68%, the amount of kerosene and terpene oil respectively were separately 400g/t and 60g/t, the reasonable pH of slurry was 8.5; the better grinding fineness under 0.074 mm of 2# was 45.11%, the amount of kerosene and terpene oil respectively were 348g/t and 66g/t, the reasonable pH of slurry was 8.5.The experiments of open-circuit flow indicated that graphite concentrate of 1# and 2# with carbon content of 96.13% and 96.49% could be respectively obtained through the process of �four-time-ballmilling and five-time-concentration�; graphite concentrate of 1# and 2# with carbon content of 95.77% and 96.01% could be separately obtained through the process of �five-time-rodmilling and six-time-concentration� and �four-time-rodmilling and five-time-concentration�. The yield of 1# graphite concentrate particles greater than 0.15 mm through the process of ballmilling and rodmilling were both less than 3%, rodmilling's little higher, with grinding efficiency far below ballmilling; The yield of 2# graphite concentrate particles greater than 0.15 mm through the process of ballmilling and rodmilling were 9.56% and 11.38%, rodmilling could offer better protection for graphite flake.The research of flotation rate demonstrated that flotation rate constant increased with the amount of kerosene and terpene and decreased with the increase of flotation concentration, the constant of 1# graphite was higher than 2#. The excessively high or low pH of slurry leaded to a lower flotation rate constant. It could achieve purpose of retrieving part of graphite flake in advance by means of controlling scraping time, increasing amount of kerosene, reducing amount of terpene oil and flotation concentration.