Hypergene Minerals Research Articles

Selection of recycled water electrochemical conditioning parameters for preparation of diamond-bearing kimberlite for froth separation

The main reason of decreasing diamond recovery through froth separation is their surface hydrophilization by hypergene minerals and technogenic films, crystallized from the supersaturated aqueous phase, fixed on the surface structurally or by adhesion. Various types of physical actions, including thermal and ultrasonic treatment of the initial feed of froth separation, are recommended to increase the diamond-bearing kimberlite beneficiation process performance, providing cleaning of the surface of diamonds due to destruction of their accretions with rock minerals and removal of film hydrophilizing coatings from the surface of diamond crystals. A sample of kimberlite material with a given content of diamonds of 1.5–2 mm in size was used as a subject of research in the process of froth separation. The results of thermodynamic calculations and experimental research have substantiated the necessity of using electrochemical conditioning of recycled water for increasing the efficiency of diamond surface cleaning in froth separation operation when using the process of thermal treatment of initial ore feed. The use of diaphragmless electrochemical conditioning of recycled water increases the efficiency of thermochemical dissolution of hydrophilizing compounds on the surface of diamonds through reducing the concentration of calcium and carbonate ions as well as through shifting the medium pH to 6.1–6.5. The measurements of the limiting wetting angle showed that the maximum effect of increasing the diamond surface hydrophobicity was achieved when heat and electrochemical treatment were used together. Laboratory studies showed the possibility of increasing flotation diamond extraction from 65.7 to 91.4 % through application of electrochemical conditioning of recycled water. The optimum parameters of diaphragmless electrochemical treatment of recycled water of the froth separation cycle in conditions of application of pulp heat treatment: current density of 175–200 A/m2 and power consumption of 1.2–1.5 kWh/m3. Tests carried out at processing plant No. 3 of the Mirny GOK (Mining and Processing Complex) (Mirny, Yakutiya) showed that the application of the developed froth separation process intensification method with the use of thermal treatment of pulp and electrochemical diaphragmless treatment of recycled water allowed increasing the recovery of diamonds of +0.5–2 mm size by 4.9–5.1 %.

Komsomolsk Tin-Ore District Mining Technogenic System and Parameters of Hypergene and Technogenic Mineral Formation Therein (Far East of Russia)

The results of modeling the conditions of crystallization of 30 hypergene (secondary) minerals from mine, drainage, and slurry waters in tin–sulfide ore mining technogenic system of the Komsomolsk District, Far East of Russia, by means of the Selektor software complex are presented. The Eh‒pH dependences for the formation and association of hypergene minerals, depending on the primary compositions of sulfide ores and their host rocks, are determined for the temperature range from ‒25 to +45°С.

Contribution of Aqueous Component to Technogenic Waters in Technogenic Mining Systems of the Dalnegorsk District

The influence of the aqueous component on the formation of slurry and drainage waters during the dry period, snowmelt, and heavy rains in the mining industrial systems of the Krasnorechensk and Central concentrating mills of the Dalnegorsk region (Primorsky Krai) has been studied. The elemental and ionic composition of mine, slurry, and drainage waters, the possibility and Eh‒pH parameters of crystallization of hypergene minerals, and their associations depending on the primary composition of ores and host rocks in the temperature range from –25 to 45°C have been simulated using Selektor software package.

МОРФОЛОГИЯ И СОСТАВ ЗОЛОТА КОР ВЫВЕТРИВАНИЯ ТОМЬ-ЯЙСКОГО МЕЖДУРЕЧЬЯ

Актуальность. Коры выветривания пород палеозойского фундамента Томь-Яйского междуречья являются потенциальными объектами промышленной добычи легко извлекаемого золота. Но морфология и состав этого золота изучены очень слабо, что затрудняет оценку уже выявленных рудопроявлений и определяет актуальность выполненной работы. Цель: исследовать химический состав и морфологические особенности самородного золота в профиле кор выветривания Томь-Яйского междуречья. Объект: самородное золото в корах выветривания по породам палеозойского фундамента Томь-Яйского междуречья. Методы. Морфологические особенности золота, парагенетические ассоциации с рудными и жильными минералами изучались микроскопически под бинокуляром, в отраженном свете. Химический состав золотин определялся методом ИСП-масс-спектрометрии и на сканирующем электронном микроскопе TESCAN VEGA 3 SBU с ЭДС OXFORD X-Max 50, на рентгено-флюоресцентном микроскопе HORIBA Scientific XGT-7200. Результаты. Выявлены две формы нахождения золота в корах выветривания и первичных рудах – свободное и связанное (невидимое) золото. Определен химический состав и проба первичного и гипергенного золота. Установлено уменьшение содержания примесных элементов и увеличение пробы в гипергенном золоте по сравнению с золотом первичной минерализации. Описаны основные морфологические типы золотин разных частей разреза коры выветривания. Предполагается присутствие гипергенного золота «бактериоморфного» происхождения. Все разновидности гипергенного золота ассоциируют с гипергенными минералами (карбонатами, глинистыми минералами, гидроокислами железа). Наибольшие содержания золота характерны для верхней части разреза коры выветривания – зоны гидролиза остаточной коры выветривания и переотложенной коры выветривания.

Происхождение гипергенных и техногенных минералов в горнопромышленных техногенных системах (на примере Дальнегорского района, Приморье)

The paper displays results of modeling the physical-chemical parameters of crystallization for hypergene minerals in mine, slurry and drainage waters within mining technogene systems of sulfide-bearing ore deposits of the Dalnegorsk district. The modeling has been carried out with the software package «Selector». Eh and pH parameters were calculated, thermal conditions of the saturation of hypergenic minerals from solutions were determined, and mineral assemblages have been distinguished. It is shown that hypergenic and technogenic minerals crystallize in the wide range of temperatures (from –25o to +40oC) with significant variations of Eh (from 0.6 to 1.2 V) and pH (0.3—13.7) values. The principal role in the formation of mineral parageneses belongs to the composition of ores and host rocks. The greater is grade of sulfides in tails of processing, the more acid solutions they are producing, and the greater is the number of newly formed secondary minerals.

Modeling Sulfide Oxidation Processes in the Vysokogorsky Tailing Dam in the Temperature Range from –25 to 0°С (Kavalerovsky District, Primorsky Krai)

The article presents the results of physicochemical modeling of the oxidation of sulfide minerals in the tailings of the Vysokogorsky tailing dam in the temperature range from –25 to 0°С, with one-by-one exclusion of sulfide minerals from the model systems. The Eh-pH parameters of the technogenic mineral formation systems have been determined at different host rock–sulfide ratios in the tailings (95: 5, 90: 10, 80: 20, and 20: 80). Crystallization of hypergene minerals have been considered, aqueous solutions qualitative and quantitative ion compositions have been determined, and their effect on the hydrosphere has been assessed.

Au-Cu-Ag mineralization in rodingites and nephritoids of the Agardag ultramafic massif (southern Tuva, Russia)

Gold-bearing albite-amphibole-pyroxene rodingites of the Agardag ultramafic massif (southern Tuva, Russia) are confined to the E-W striking serpentinite crush zone. A zone of gold-bearing nephritoids is localized at the contact of rodingites with serpentinites. Optical and scanning electron microscopy, electron probe microanalysis, and fluorescent, chemical, ICP MS, and X-ray phase analyses were applied to study Au-Cu-Ag mineralization in the serpentinites, rodingites, and nephritoids. Copper sulfides, chalcocite and digenite, are present in the serpentinites, whereas gold and silver minerals are absent. Copper impurity is found in antigorite, Cr-spinel, and magnetite (up to 0.1-0.3 wt.%) as well as parkerite (up to 1.2 wt.%) and millerite (up to 7.9 wt.%). A wide variety of native gold and copper minerals has been identified in the rodingites: (1) cuproauride and tetra-auricupride free of or containing silver impurities (0.1 to 1.2 wt.%); (2) electrum of composition Ag0.50-0.49Au0.50-0.51 (650-660%c) intergrown with AuCu, sometimes as exsolution structures; (3) electrum of composition Ag0.70-0.64Au0.30-0.36 (440-510%c), with inclusions of AuCu and copper sulfides (geerite and yarrowite); (4) high-fineness gold (750-990%c) as veinlets in electrum; and (5) native copper. The composition of copper sulfides varies from chalcocite to covellite. Submicron inclusions of hessite Ag2Te were found in chalcocite. The amount of copper, gold, and silver minerals in the nephritoids is much less than that in the rodingites. The nephritoids contain chalcocite, electrum of composition Ag0.64-0.63Au0.36-0.37 (530-540%c), cuproauride, and tetra-auricupride. The detected hypergene minerals are auricuzite, apachite, brochantite, high-fineness gold, native copper, and cuprite. The sequence of mineral formation in the Agardag ore occurrence has been established on the basis of mineral structures and mineral relations in the rodingites and nephritoids. It is proved that Au-Cu-Ag mineralization formed with the participation of Au- and Ag-bearing chloride-free low-sulfur carbon dioxide alkaline fluids in reducing conditions.

Assessment of the Impact of Technogenic Processes Occurring at the Central Concentrating Mill Tailing Dump (Komsomolsky Tin-Ore District) on the Hydrosphere in a Wide Temperature Range

The results of physicochemical modeling of oxidation of sulfide minerals in the Central Concentrating Mill tailing dump (Komsomolsky tin-ore district) with account taken of the cementation zone in the temperature range from–25 to +45°C are given. The Eh-pH parameters for the formation of micropore solutions in technogenic systems have been determined at different host rock–sulfide ratios (95: 5, 90: 10, 80: 20, 60: 40, 40: 60, 20: 80, 10: 90, 5: 95). Crystallization of hypergene minerals from the micropore solutions have been considered, their qualitaitve and quantitative ion compositions have been determined, and their effect on the hydrosphere has been assessed.

Modeling the compositions of slime waters in the tailing dumps of the Central and Krasnorechensk concentrating mills at the Dal’negorsk district in the positive temperature range

The paper describes the physicochemical modeling of slime water formation in the dried tailing dumps of the Central and Krasnorechensk concentrating mills in the positive temperature range. The Eh and pH parameters of the equilibrium solutions, quantitative element compositions of the latter, and the compositions of the crystallizing hypergene and technogenic minerals were determined. The modeling was carried out on the basis of the averaged chemical compositions of the tailings. The resulting data point to a possible hydrosphere pollution with slime waters containing elements of sulfide ores and enclosing rocks, which may occur over the entire considered temperature range, both before hypergene mineral deposition and after that.

Impact Assessment of the Sulfide Oxidation Processes Occurring in the Tailing Dumps of Komsomolsky District on the Hydrosphere in a Wide Temperature Range

The article describes the modeling results of drainage water in the tailing dumps of Komsomolsky tin ore district in the temperature range from-10 to +45 °C. Eh-pH parameters of technogenic mineral systems for different ratios of host rock - sulfides (95:5, 90:10, 80:20 and 60:40) in the tailings were determined. The process of hypergene mineral crystallization from micropore solutions was researched, its qualitative and quantitative ion composition was established and its impact on surface and ground water of the district was showed.

Отличительные черты гипергенного изменения пород различного состава

Comparative complex analysis of different types of weathering crust indicates that the following three factors along with mineralogical peculiarities of primary rocks and hydrogeochemical conditions are of great importance for formation of eluvial material. First factor is a degree of structural ordering of primary minerals. A second one is related to an inheritance of properties by new mineral phases. The third factor includes a universalism of processes of transformation of hypogene and formation of hypergene minerals in the weathering crusts developed in different types of rock. Realization of these basic assumptions can be achieved only with their integrated optical-electronic microscopy and structural-crystal-chemical investigations. This methodology allows distinguishing between the varieties of the same primary minerals using their structural specific features, as well as identifying secondary layered silicates formed at different stages of rocks hypergene alteration.

Crystal structure interconnections in a family of hydrated phosphate-sulfates

The phosphate-sulfate family incorporates several water-containing hypergene minerals with various structures. We determined the crystal structure of lately discovered [1] fibrous mineral arangasite, [Al2F(H2O)6(PO4)(SO4)]·3(H2O) using single-crystal synchrotron diffraction at 100 K (a =7.073(1), b=9.634(2), c=10.827(2) Å, β=79.60(1)0, P2/a, Z=2). Its crystal chemical interpretation has allowed us to reveal some interesting features in a title group of compounds. The arangasite crystal structure is dominated by chains extending in the [100] direction and built of pairs of corner-shared Al octahedra joined through bridging F atoms and P tetrahedra. They alternate in the [001] with S tetrahedra forming layers parallel to the ac plane through a system of hydrogen bonds. Along [010] the complex layers are separated by layers of H2O molecules. Hydrogen bonding serves here as the only mechanism providing linkage between the main structural fragments. The Al/ P chains are topologically identical to the chains built from Fe octahedra and P tetrahedra in the triclinic structure of destinezite, Fe2(OH)(PO4)(SO4)(H2O)6[2]. The repeating subunit of both chains consists of two octahedra and one tetrahedron sharing vertices. A main difference among the chains arises from their chemistry; Al octahedra in arangasite form pairs by sharing the F vertex of neighboring polyhedra, whereas pairs of Fe octahedra in destinezite are linked together through the oxygen vertex of an OH group. As a result, the larger size of the Fe octahedra compared to Al octahedra causes a larger c = 7.31 Å along the chain in destinezite. Additional SO4tetrahedra here are attached to these chains along their periphery through an oxygen vertex bridge with Fe octahedra. The monoclinic sanjuanite, Al2(PO4)(SO4)(OH)(H2O)9structure [3] is composed of Al/P chains, parallel to a = 6.11 Å. These chains are also built from three-member units that include corner-sharing pairs of octahedra connected by PO4tetrahedron, but they are not topologically equivalent to the chains in the arangasite and destinezite structures. Similar to arangasite, sulfate groups and H2O molecules reside between chains in the sanjuanite structure with hydrogen bonding. Thus, similar the crystal chemical formulae of sanjuanite and arangasite differ with respect to the (OH) → F substitution, which results in contrasting unit cell parameters. Note, that the unit cell volume of sanjuanite, is twice as large as arangasite.

Temperature Effect on the Hypergene Mineral Formation Process (The Case of Tailing Dumps of Komsomolsky Tin-Ore District)

Physicochemical modeling of drainage water in the tailing dumps of Komsomolsky tin ore district in a wide temperature range from-10 to +45 °C obtained in the article let to find Eh-pH parameters of micropore solutions from which technogenic and hypergene minerals crystallize. The modeling was made for different ratios host rock – sulfides (95:5, 90:10, 80:20 and 60:40). Qualitative and quantitative ionic composition of the solutions was determined and their impact on the surface and ground water of the area was showed.

Evaluation of Technogenous Processes Proceeding in Tailing Dump of the Central Concentrating Mill of Dal’Negorsk District and their Effect on the Hydrosphere with Method of Physicochemical Modeling

Modeling allowed us to show Eh-pH parameters of the technogenic mineral formation in the mining-industrial technogenic system of polymetallic ores of Dal’negorsk district, to study the process of the hypergene mineral crystallization from solutions, to consider the qualitative and quantitative ionic composition of solutions, to show the role of hypergenesis in the contamination of surface and ground waters of the area. The aim of this work is to estimate the action of the CCM tailing oxidation on the hydrosphere of the district using the method of physicochemical modeling. The results obtained testify to a significant evacuation of a wide range of elements of sulfide ores (Zn, Pb, Cu, As, S) and enclosing rocks (Si, Al, Mg, Ca, K, Na) from the CCM tailing dumps into the surface waters polluting the hydrosphere with them.

Estimation of Effect of Hypergene Processes Proceeding in the Mining-Industrial Technogene System on the Hydrosphere of Dal'negorsk District Using Physicochemical Modeling Method (Primorsky Region)

Estimation of the effect of hypergene and technogene processes proceeding in the ore bodies of the mining excavations and the tailings of the old tailing dump of the Krasnorechenskaya concentrating mills of Dalnegorsk district showed that mineralization of solutions in all modeling systems is high. This allows the hypergene minerals to be crystallized from the solutions. The solutions form the mine and drainage waters, in which the content of sulfide elements is tens, hundreds, thousands, and even tens of thousands times higher than the background characteristics.

Estimation of the Tin-Sulfide Tailing Effect on Hydrosphere with Physicochemical Modeling (Komsomolsk Area)

Modeling carried out by the authors made it possible to show the system parameters, to study the process of the hypergene mineral crystallization from solutions, to take a look at their qualitative and quantitative ion composition, to show the hypergenesis role in the pollution of the surface and ground waters of the district, and to estimate it.

Physicochemical Modeling of Hypergene Mineralization Processes in the Solnechnaya Reclamation Plant Tailing Dump (Khabarovsky Region) in the Temperature Range from -5 to +45 °C

The article presents the results of physicochemical modeling of hypergene processes in the tailing dump of the Solnechnaya Reclamation Plant (SRP). The effect of temperature factor on the hypergene minerals crystallization and pore solutions formation was researched.

Gold in the weathering crust at the Suzdal' deposit ( Kazakhstan)

A comparative analysis of morphology and geochemistry was made for gold from the primary ores and weathering crust of the Suzdal' gold deposit, Eastern Kazakhstan. The deposit is localized in Carboniferous carbonaceous-terrigenous strata and is of gold-sulfide type. Study of gold from primary ores showed that it occurs mainly in two species: free and so-called invisible. Free gold is crystallomorphic segregations and irregular-shaped grains up to tens of microns in size; it occurs in intergrowths with sulfides, quartz, carbonate, and mica-chlorite aggregate. Most of gold particles have a fineness of 930–980‰, with some grains showing wide variations in composition. Invisible gold (probably chemically combined) is present in fine-acicular arsenopyrite and, less frequently, pyrite. Being transported to the weathering crust, all this gold served as a source for “neogenic” gold of diverse morphologic forms. We recognized crystalline (isometric, prismatic, acicular, and tabular) particles and drusoid gold aggregates in the form of exotic intergrowths of crystallomorphic and sinter-shelly grains. The grains tend to coarsen from bottom to top of the weathering crust. Several generations of gold of different granulometric classes are observed. We have revealed seed and layer growth and dissolution structures in crystals of early generations overgrown with fine grains. All these gold varieties are associated with hypergene minerals. Most of this gold is of high fineness (on the average, 995‰). The hypergene gold particles are chemically homogeneous high-grade, without rims. The results of studies suggest that the high-grade hypergene gold formed in the weathering crust as a result of the dissolution of invisible gold of sulfides and its local redistribution and deposition in oxidizing media. This is also evidenced from the tendency of gold to coarsen from bottom to top of the weathering crust. A distinctive feature of secondary gold is well-expressed crystals and their great diversity.

MINERALOGY OF WEATHERED BASALT CRUST IN WEST VOLYNYA

This article describes the weathered crust of extrusives of basic composition developed in West, Volynya; Four different weathered Crust zones are distinguished on the basis of the degree of mechanical disintegration and hypergene alteration of the rocks. The article gives a petrographic and Mineralogic description of the individual Zones as well as an account of the principal minerals in the hypergene complex. The reasons are given for the disproportionate amount of various flows in the weathered crust. Genesis of the weathered crust as a whole is discussed, and also the processes which determine the nature of the individual zones. The zonation of the layered silicates (celaclonite, mountain leather, chlorite, and minerals of the montrnorillonite group, and halloysite) and other hypergene Minerals is mainly determined by the pH value of the solutions The weathered basalt crust of West Volynya is a typical case of a crust formed over a long period on basic rocks in a warm and humid climate. — Auth.