Timing of granite pegmatite-type high-purity quartz deposit in the Eastern Qinling,China:constraints from in-situ LA-ICP-MS trace analyses of quartz and monazite U–Pb dating

Eastern Qinling,China is one of the important rare metal metallogenic provinces with extensively distributed granite pegmatite dikes.The No.5 granite pegmatite intruded into the granitic gneiss of the Qinling Group,and the major minerals are quartz(39.8%),K-feldspar(18.8%),albite(36.3%),muscovite(3.4%),and garnet(1.1%).Monazite U–Pb isotopic dating indicates that the No.5 pegmatite from the Eastern Qinling was emplaced at ca.420.2±2.2 Ma,which confirms that highpurity quartz mineralization probably formed during the Early Devonian.In-situ laser ablation inductively coupled plasma mass spectrometry analysis of quartz show that quartz samples from Eastern Qinling have total trace element concentrations(Al,Ti,Sc,Li,B,Cr,Mn,and Fe)ranging from 23.2 to 52.8 ppm,slightly higher than the quartz(impurity element content from 13.4 to 25.9 ppm)of the Spruce Pine high-purity quartz deposit in western North Carolina.The No.5 pegmatite of Eastern Qinling could be defined as one high-purity quartz deposit of China.

Separation of tungsten and molybdenum with solvent extraction using functionalized ionic liquid tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate

Functionalized ionic liquids(FILs)as extractants were employed for the separation of tungsten and molybdenum from a sulfate solution for the first time.The effects of initial pH,extractant concentration,metal concentrations in the feed were comprehensively investigated.The results showed that tricaprylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate([A336][Cyanex272])could selectively extract W over Mo at an initial pH value of 5.5;the best separation factorβ_(W/Mo) of 25.61 was obtained for a solution with low metal concentrations(WO3:2.49 g/L,Mo:1.04 g/L).The[A336][Cyanex272]system performed effectively for solutions of different W/Mo molar ratios and different metal ion concentrations in the feed.The chemical reaction between[A336][Cyanex272]and W followed the ion association mechanism,which was further proved by the Fourier-transform infrared(FTIR)spectra of loaded[A336][Cyanex272]and the free extractant.The stripping experiments indicated that 95.48%W and 100.00%Mo were stripped using a 0.20 mol/L sodium hydroxide solution.Finally,the selective extractions of W and Mo from two synthetic solutions of different high metal concentrations were obtained;the separation factorβW/Mo reached 23.24 and 17.59 for the first and second solutions,respectively.The results suggest the feasibility of[A336][Cyanex272]as an extractant for the separation of tungsten and molybdenum.

Study of orientation and morphology of elliptical particles in drum granulation by dynamic simulation

Sphericity is an important indicator of particle flow properties in rotary granulation. Here, a dynamic simulation approach is proposed to study the formation of particle sphericity during agglomeration by investigating both the orbit and attitude of non-spherical particles in a rotary drum. First, geometric crite- ria are presented to substitute a dual-sphere particle model for the commonly encountered ellipsoidal particle model assuming the long radius of the dual-sphere particle is equal to that of the ellipsoidal particle. Next, a discrete element method is applied to calculate the positions and orientations of dual- sphere particles during granulation. The relationship between shape and attitude in the dual-sphere model is then analyzed by comparing the obtained orientation angle-oblateness curves. A conclusion can be drawn that the particle orientation angle decreases with increasing particle oblateness within a certain range.

A new technology for processing niobite ore found in Jiangxi province

A new process is proposed for refining niobite ore that is found in Jiangxi province of China. Niobite, also known as columbite or niobite-tantalite, is a mineral that contains tantalum and niobium. The separation process includes two-stage grinding, gravity concentration, magnetic separation, and flotation. The tan- talum/niobium concentrate obtained had a grade of Ta2O5 18.28%, Nb2O5 41.62% at a recovery rate of Ta2O5 49.08%, Nb205 70.77%. Other minerals occurring along with the niobite, such as zinnwaldite, feld- spar, and quartz, were also recovered to comprehensively utilize this ore.