Selective flotation of scheelite from calcite using xanthan gum as depressant

Differential adsorption of hydrolytic polymaleic anhydride as an eco-friendly depressant for the selective flotation of apatite from dolomite

Quartz, the second most abundant mineral in the earth’s crust, is a gangue mineral in practically every flotation process. Coarse quartz flotation has been a long standing problem in various mineral processing plants to reduce milling cost and increase valuable mineral recovery. Based on this, the effects of nanobubbles (NBs) and hydrodynamic parameters on coarse quartz particle flotation were systematically investigated. Mechanical flotation experiments were carried out using the 7 cm and 9 cm diameter impellers in order to produce different hydrodynamic conditions. 900–1300 rpm impeller speeds were used for the 7 cm diameter impeller and 554–786 rpm for the 9 cm diameter impeller. The results show that the presence of NBs increased the flotation recovery of −425 + 106 μm quartz by up to 21%. For the 7 cm diameter impeller, the maximum flotation recoveries of 86.4% and 98% were obtained in the absence and presence of NBs at Reynolds number (Re) of 81,000 and 66,000, respectively. For the 9 cm diameter impeller, the maximum recoveries of 86.3% and 97.5% were obtained in the absence and presence of NBs at Re of 90,000 and 75,000, respectively. NBs increased the flotation rate constant up to 36%.

Effects of nanobubble and hydrodynamic parameters on coarse quartz flotation

Iron tailings is the most common and largest mining waste, and given the serious social, economic, and environmental impacts caused by tailings, green and safe technologies are urgently needed for the efficient treatment of tailings. In the present work, efficient extraction of iron from flotation tailings via the suspension magnetization roasting and magnetic separation has been demonstrated as a promising way to reduce emissions and extracting iron from flotation tailings. The possibility of iron extraction from flotation tailing containing 21.86% iron and transformation mechanism were studied in a pilot-scale experiment. The results revealed that an iron concentrate having an iron grade of 66.51% and iron recovery of 72.90% could be obtained under the following conditions: roasting temperature of 470 °C, reductant concentration of 30%, reductant ratio of 1:1 (CO: H2), and total gas flow of 16.0 m3/h. The mineralography and magnetic performance of the preconcentration concentrate, roasted product, magnetic concentrate, and magnetic tailings were studied by X-ray diffraction, iron chemical phase analysis, and the vibrating sample magnetometer. The effect of roasting on the microstructure of the products was also analyzed by scanning electron microscopy and laser particle size analysis to help understand the mechanism.

Pilot-scale extraction of iron from flotation tailings via suspension magnetization roasting in a mixture of CO and H2 followed by magnetic separation

Selective adsorption of an eco-friendly and efficient depressant PBTCA onto dolomite for effective flotation of fluorapatite from dolomite

Improving flotation separation of apatite from dolomite using PAMS as a novel eco-friendly depressant

Interactions between fine and coarse hematite particles in aqueous suspension and their implications for flotation

An investigation of the mechanism of using iron chelate as a collector during scheelite flotation

Scheelite associated with calcium-containing minerals such as calcite and fluorite is difficult to separate by flotation because of the Ca ions contained in the mineral lattices, which cause scheelite to have similar surface properties and floatability to gangue minerals. Traditional collectors such as oleic acid need to add a large amount of sodium silicate as gangue inhibitors, which causes difficulties for the settlement of tailings. In addition, the use of benzohydroxamic acid (BHA), which needs the addition of Pb(NO3)2 as the scheelite activator, can also cause environmental pollution. In this paper, Fe-BHA, a new collector containing the iron complex, was studied to investigate its flotation ability of scheelite, as well as its BHA/FeCl3 ratio on scheelite flotations. In the single mineral flotations, the Fe-BHA showed a significant difference in the flotation recoveries of scheelite and calcite, with a scheelite recovery of 77.03% at pH 8.0 and calcite recovery of 16.69% at the same pH. The results of the roughing tests of Xianglushan actual ore showed that the scheelite with Fe-BHA (500 g/t BHA and 200 g/t FeCl3) and 40 g/t oleic acid as collectors obtained satisfactory flotation results with a WO3 grade of 1.56% and WO3 recovery of 65.52%, which were much higher than those of scheelite with BHA or oleic acid as the collector, but there was still a gap with those of scheelite using Pb(NO3)2 as activation and BHA as the collector. The UV-Vis curves of the Fe-BHA with different BHA/FeCl3 ratios indicated that the Fe-BHA chelates might have several different structural forms, and the single mineral tests of the BHA/FeCl3 ratios showed that when the molar ratio of benzohydroxamic acid to FeCl3 was about 1.2:1, the best scheelite flotation result was obtained in this test. In addition, the XPS analyses proved that the adsorption of the Fe-BHA on the scheelite surface occurred, and by fitting the peaks of Ca 2p and O 1s of scheelite, it was found that the mechanism of the Fe-BHA acting on the Ca sites of the scheelite surface was through the removal of H2O from the Ca-OH of scheelite and Fe-OH from Fe-BHA to form Fe-O-H.

/pdf/study-of-the-mechanism-of-the-fe-bha-chelates-in-scheelite-389ocste.pdf

Study of the Mechanism of the Fe-BHA Chelates in Scheelite Flotation

The invention discloses a fluorapatite purification method and a method for preparing a fluorohydroxyapatite bioceramic, and belongs to the technical field of mineral processing. The fluorapatite purification method comprises the following steps that the fluorapatite ore is ground, stirred and slurried, adjusted to pH value, added with an inhibitor and a collector, and inflated for rough selectionto obtain a coarsely selected concentrate and a coarsely selected tailings; the coarsely selected concentrate is slurried, adjusted to pH value, and added with the inhibitor for selection to obtain afluoroapatite concentrate and a selected tailings; and the fluoroapatite concentrate is added with water and slurried and then added with phosphoric acid leaching, solid-liquid separation is carriedout, and the purified fluoroapatite is obtained after drying. The purified fluoroapatite is added with water and stirred to remove the agent, concentrated nitric acid is added to dissolve, NaOH is added to carry out hydroxy reaction, and after calcination and crystallization, the fluorohydroxyapatite bioceramic is obtained. The method obtains the synthesized fluorohydroxyapatite which is used as ahuman body hard tissue substitute material, and the method has the characteristics of being low in production cost, simple in process, easy to operate and the like.

Chen Zhao

Papers

Improving flotation separation of apatite from dolomite using PAMS as a novel eco-friendly depressant

Interactions between fine and coarse hematite particles in aqueous suspension and their implications for flotation

An investigation of the mechanism of using iron chelate as a collector during scheelite flotation

Study of the Mechanism of the Fe-BHA Chelates in Scheelite Flotation

Fluorapatite purification method and method for preparing fluorohydroxyapatite bioceramic thereof