Quartz Recovery Research Articles

液‐液抽出法による微細鉱物粒子の回収に関する基礎的研究

The effect of the organic phases on the recovery of fine quartz particles by liquid-liquid extraction at various pH has been investigated using dodecylamine acetate (DAA) as a collector. Three kinds of organic solvents, n-butanol, methyl isobutyl ketone (MIBK) and iso-octane, were used as the oil phase in the present study. The interactions between the oil droplets and the quartz surface under different conditions of pH and DAA concentration have been examined through the related studies on the oil/water interfacial tension, contact angle and interfacial free energy for oil droplets to contact at the quartz surface in water. Good correlation was obtained between the percentage of quartz recovery and these variables. The recovery depends not only upon pH and collector concentration, but upon the properties of oil phase.

Moisture of air and efficiency of dry magnetic separation

The authors mathematically formulate the efficiency of a magnetic separator for the recovery of magnetite and quartz and assess the effect of atmospheric humidity and consequent ore moisture on losses in efficiency in the separator. They propose a preliminary drying treatment and justify the expenditure of energy this requires by demonstrating that the overall efficiency of the drying and the consequent moisture-free separation process exceeds the efficiency of the separator when moisture is allowed to remain a factor in the process.

モノアミン, ジアミンおよびトリアミンによるヘマタイトからの脱珪浮選に関する基礎的研究

Flotation experiments of fine particles (-10μm) of quartz and hematite were carried out as a function of pH using mono-, di-, and triamine acetates as collectors by Denver-type laboratory flotator. Amines used were dodecyl amine (C12H25NH2), dodecylpropylene diamine (C12H25NH (CH2) 3NH2), and dodecyldipropylene triamine (C12H25NH (CH2) 3NH (CH2) 3NH2), respectively. Dissociation constants of diamine and triamine were determined by pH titration according to the Schwarzenbach's method. Reverse flotation of quartz from an artificial mixture (1: 1 by weight) with hematite was also carried out by varying the collector concentration in both acidic and alkaline media.1) As dissociation constants, pKα1 10.2 and pKa2 11.3 for diamine, and pKα1 9.0, pKα2 10.1, and pKα3 11.3 for triamine were obtained, respectively.2) Individual flotation tests showed that, in acidic media, flotation recovery of quartz increased with the increase of the number of amino radical of collectors, while no appreciable difference in flotation recovery of hematite was indicated. In alkaline media, flotation recoveries of quartz were enhanced with diamine and triamine, and floatability of hematite increased with increasing the number of amino radical of collectors.This flotation behavior was explained by an electrostatic interaction between surface charges of minerals and positive charges of collectors resulting from their dissociation.3) Reverse flotation of quartz from an artificial mixture was impossible in acidic media (pH=5) because of heterocoagulation of quartz and hematite.Better results of reverse flotation were obtained in alkaline media (pH=10) using diamine and triamine in comparison with those using monoamine.Reverse flotation tests at pH=10 and at a collector concentration of 5×10-5M showed that the flotation rate of quartz increased while that of hematite decreased with increasing the number of amino radical of collectors.

Some physical properties of amorphous SiO2 synthesized by shock compression of α quartz

The amorphous phase of SiO2 produced upon recovery of shock-compressed quartz demonstrates a wide range of refractive indices which can be correlated to the shock state. Both infra-red absorption spectra and X-ray diffraction patterns indicate that the shock-produced amorphous SiO2 has a statistically more-random atomic distribution and longer Si-O and shorter Si-Si separation than does fused silica. By accounting for phase transformation, the calculated values of the shock and residual temperature are much higher than those obtained by Wackerle (1962) to a pressure of 700 kbar. Our results are consistent with experimental ones.

Quartz, Feldspar, and Mica Determination for Soils by Sodium Pyrosulfate Fusion

AbstractSoil fractions are treated with the J. Lawrence Smith Na2S2O7 fusion which is shown to decompose micas and other layer silicates common in soils. The layer silicate relics are dissolved by washing with 3n HCl and hot 0.5n NaOH for 2.5 min leaving quartz and feldspar in the residue. Recovery of quartz after the treatment ranged from 99.4% in the 50 to 20µ fraction to 96.6% in the 2 to 0.2µ fraction; correction factors are applied to the respective fractions accordingly.Recovery of K feldspar ranged from 96.5% in the 500 to 50µ fraction to 64% in the 2 to 0.2µ fraction; Na feldspar recovery varied from 95% in the 500 to 50µ fraction to 68% in the 2 to 0.2µ fraction. Highly calcic feldspars (bytownite, An 70–90, and anorthite) were completely dissolved in the finer fractions but such feldspars are uncommon in soils. Labradorite (An 50–70) is determinable in fractions coarser than 5µ. Feldspars are determined by allocation of residue K, Na and Ca to their equivalent endmember feldspars, with suitable correction factors for mineral solubility and for increase of Na from pyrosulfate in K and Ca feldspars. The remainder of the residue is allocated to quartz. Mica K2O is obtained as the difference of total K2O less feldspar K2O in the residue, a differentiation important to soil fertility.Quartz is almost invariably present with layer silicates in soil clays. As much as 15% quartz frequently is undetectable in X‐ray diffractograms in the presence of appreciable mica, because of the coincidence of the 3.35A peak of quartz with the 3.33A peak of micas and because the 4.26A quartz peak is relatively weak. The quartz present can be determined by the proposed method to within ± 1% in samples low in feldspars.

DETERMINATION OF FREE SILICA: GRAVIMETRIC AND SPECTROPHOTOMETRIC PROCEDURES APPLICABLE TO AIR-BORNE AND SETTLED DUST.

Abstract Refinements contributing to the precision and accuracy of the phosphoric acid method can be made by the use of commercially available apparatus comprising a rotator and a voltage-controlled heater. Additional refinements include optimizing the conditions of analysis by digestion of orthoclase with phosphoric acid for varying lengths of time, use of correction curves to compensate for loss of quartz, and identification of undissolved minerals by means of a polarizing microscope. An eight-year study of the precision of the phosphoric acid method gave a mean standard deviation of 0.34 in the analysis of typical samples containing from- 3 to 50 per cent quartz. The recovery of quartz from the less-than-5-micron fraction of air-borne dust is about 95 per cent when the digestion time is reduced to 8 minutes. The method can be extended to samples of air-borne dust as small as 2 milligrams by spectrophotometric determination of the quartz as molybdisilicic acid.