Scrubbing and Inhibiting Coagulation Effect on the Purification of Natural Powder Quartz

Abstract

The low removal efficiency of fine clay impurities in natural powder quartz (NPQ) is the main problem that affects the practical utilization of this natural resource. In this work, detailed characterizations of NPQ and clay impurities in NPQ were analyzed by SEM-EDS, mineral liberation analysis (MLA) and impurities distribution analysis. A combined physical purification process, including sieving, scrubbing and centrifugation, was applied to remove the clay impurities. It was observed that the fine clay impurities adhering on quartz surface were effectively liberated by scrubbing, and the content of Fe 2 O 3 and Al 2 O 3 in the concentrate decreased from 0.48% and 0.40% to less than 0.01% and 0.02% at pH 9.3 or when the dosage of sodium hexametaphosphate (SHMP) was 1 × 10 3 g/t. The coagulation interaction between quartz and impurities including hematite and orthoclase were analyzed based on the classical Deyaguin-Landau-Verwey-Overbeek (DLVO) theory. The results indicated that the main coagulation affecting the separation efficiency was the heterocoagulation between quartz and impurities and homocoagulation among hematite particles. Furthermore, adding regulators such as sodium hydroxide (NaOH) or SHMP could significantly decrease the zeta potential of minerals and thus increase the total interaction energy (V T ), which could effectively improve the dispersion of these fine impurity particles, and consequently improve the removal efficiency of impurities. Reverse increase of the zeta potential of minerals in strongly alkaline solutions or excessive SHMP were detected, which was likely the main factor limiting the further improvement of the purification efficiency.

Editorial for the Special Issue: “Physical Separation and Enrichment”

“…Du et al [14] also contributed to this Special Issue by discussing scrubbing and the inhibiting coagulation effect on the purification of quartz particles. The low removal efficiency of fine clay impurities in natural quartz is the main problem affecting the practical usage of this resource.…”

Advanced Processing Techniques and Impurity Management for High-Purity Quartz in Diverse Industrial Applications

“…The genesis of quartz deposits is influenced by multifarious factors, culminating in substantial disparities in quartz concentration, impurity mineral typologies, and their respective levels across geographies. Typically, indigenous quartz deposits harbor a plethora of impurity minerals, encompassing iron minerals (notably hematite and limonite), rutile, calcite, mica, feldspar varieties (including potassium and sodium feldspar), and clay minerals, among others [3]. During geotectonic processes, quartz crystals, with entrapped solid and fluid inclusions of metallic impurities, gases, and aqueous molecules, significantly enhance the impurity quotient of quartz silicates [4][5][6].…”

“…(2) Pegmatite Quartz: derived from pegmatites, these quartz crystals can be exceptionally pure, often used for high-end electronic and optical applications [10][11][12][13]. (3) Hydrothermal Vein Quartz: formed from hydrothermal fluids, this type includes vein quartz with high SiO2 content but can have numerous gas-liquid inclusions and associated minerals like pyrite, hematite, mica, and feldspar [14]. (4) Metamorphic Quartz: includes quartzites and metamorphogenic mobilizates formed under high-pressure and high-temperature conditions, often resulting in high-density, hard quartz with some impurities like iron minerals, feldspars, and clay minerals [15].…”

Whitening of calcium carbonate tailings using attrition process: a case study of Khar Toum deposit, Lopburi province, Thailand

“…The attrition scrubbing process was applied to remove clay mineral that contained Al 2 O 3 and Fe 2 O 3 from quartz including silica sand (Aguiree-Villafana & Leal-Gonzalez, 1994;Du et al, 2019;Raghavan et al, 2006). The parameters that were studied are retention time and solid percentage.…”

“…The parameters that were studied are retention time and solid percentage. For retention time, Du et al (2019) treated quartz by attrition scrubbing process at retention time of 25 min. The result showed that the Al 2 O 3 and Fe 2 O 3 was decreased from 0.040% and 0.048% to 0.033% and 0.020%, respectively.…”