Wyniki wyszukiwania - BazTech

1

Optimizing the removal of iron oxide from Egyptian feldspar ore

Yassin E. Khaled, Elbendari A.M., Hassan El-Sayed R. E.

Physicochemical Problems of Mineral Processing

|

2023

|

Vol. 59, iss. 6

art. no. 176420

EN

The demand for feldspar as a raw material for various industrial applications continuously increases. Feldspar is a primary raw material in manufacturing ceramics, glass, fillers, welding electrodes, and enamel. Feldspar is often associated with iron oxide, which decreases its economic value and hinders its industrial application. The present work aimed at reducing iron oxide content in Egyptian feldspar ore from the Wadi Zerabi locality. Ball milling was used for preparing feldspar feed of size -250+45μm. Carpco dry high-intensity magnetic separation followed by acid leaching processes were carried out in order to decrease the iron contamination and increase the feldspar content. A Box-Behnken statistical design was used to optimize the magnetic separation results. From a feldspar feed containing 1.40% Fe2O3, a non-magnetic concentrate of 0.25% Fe2O3 was obtained. The Fe2O3 removal reached up to 82% with a high yield as the % weight of non-magnetic feldspar reached up to 97.5%. The leaching process further reduced the iron oxide content down to 0.19 %. Also, the feldspar whiteness was improved from 65.17% in the original ore to 85.60% in the leached product.

2

Comparative study on removal of metallurgical silicon impurities by different acid leaching methods

Gao Zijie, Luo Dawei

Physicochemical Problems of Mineral Processing

|

2023

|

Vol. 59, iss. 2

art. no. 162331

EN

Hydrometallurgy is considered a promising method to produce solar-grade silicon (SOG-Si) from metallurgical-grade silicon (MG-Si) due to its advantages of low cost, simple operation, and easy control. In this paper, the effects of particle size of MG-Si, type of acid, leaching time, temperature, and liquid-to-solid ratio on the purification efficiency were investigated in an external field environment with the addition of ultrasound. The purification efficiencies of the two acid-leaching methods were compared. It was found that the simultaneous use of HCl + HNO3 was more effective than using only HCl for impurity removal in MG-Si: the extraction efficiencies of impurities Fe and Al were increased by 2.2% and 13.4%, respectively. The impurity contents in MG-Si before and after calcination pretreatment were also compared. This paper is expected to help researchers select the appropriate hydrometallurgical technique to reduce the impurity content in MG-Si.

3

An experimental study of removing impurity from a quartz ore by microbial flotation-acid leaching

Zhu Jujian, Dai Shujuan, Li Pengcheng, Yang Shuyong

Physicochemical Problems of Mineral Processing

|

2021

|

Vol. 57, iss. 1

18--28

EN

The purity of a quartz ore is relatively low at a SiO2 content of 97.18%, and the main impurity in the ore is Fe, Al, and Ca bearing minerals. The main component in an industrial waste bacteria (WJ) is polysaccharides, which may be used as depressors for inhibiting iron minerals in quartz flotation. Moreover, WJ belongs to microbial inhibitors because it is mainly composed of bacteria. As a result of this study, a concentrate grade of 99.88% at recovery over 80% was obtained under the condition of 2000 g/Mg WJ dosage, a grinding fineness of 70% -0.074 mm, pH 11.7, 400 g/Mg CaCl2, and 800 g/Mg NaOL in the flotation experiments for the quartz ore. Moreover, a SiO2 grade of 99.97% at a recovery of 68.85% was obtained at an acid dosage of 40 kg/Mg by using mixed acid of H2SO4, HCl, HNO3, and HF in mass ratios of 20%, 30%, 20%, and 30%, respectively, in subsequent acid leaching of the quartz flotation concentrate. Zeta potential analysis before and after the interaction of quartz and hematite with WJ showed that WJ increased the zeta potential of hematite significantly but had little impact on the zeta potential of quartz, indicating stronger adsorption of WJ on hematite than on quartz. FTIR analysis showed that there exist not only –COOH, –CH2–, and –CH3, which are the functional groups of starch but also NH2 and –C=O-NH– in WJ. The NH2 and –C=O-NH– in WJ are the important groups for adsorption, so the depressing effect on hematite was better for WJ than starch.

4

Zinc extraction from Ghazouat leach residues by using jarosite method

Begar Abdelhakim, Djeghlal Mohamed El Amine, Ould Hamou Malek

Mining Science

|

2021

|

Vol. 28

117--126

EN

In this paper, it was aimed to select and propose a feasible as well as an applicable method, for the extraction of zinc that was present in the disposed GHAZOUAT leach residues having 17.82 wt. % Zn and 20.82 wt. % Fe. After the determination of the components of the residue, the acid leaching was performed to reclaim Zn sequentially. The acid leaching experiments were carried out for Zn extraction by controlling acid concentration, reaction duration and temperature. At the optimum conditions, 240 g/L H2SO4 at 90 °C for 210 min, 80% of initial iron content was removed, and the resultant overall zinc extraction was usually superior than 96%.

5

Non-reductive acidic leaching as a method for recovery of zinc and manganese from Zn-C and Zn-MnO2 battery waste

Sobianowska-Turek Agnieszka, Banaszkiewicz Kamil, Pasiecznik Iwona, Marcinkowski Tadeusz, Urbańska Weronika

Environment Protection Engineering

|

2021

|

Vol. 47, nr 2

17--29

EN

The dynamic growth of mobile technologies is a driving need for portable power sources. The most popular division of electrochemical cells relies on the type of chemical reaction within the cell. Current data coming from the Polish market show that despite the growth in the sale of secondary power sources, zinc-carbon and alkaline batteries are still the most popular. The results of non-reductive acidic leaching of zinc and manganese from the waste batteries stream have been presented. Manganese was leached with almost 100% yield in an experiment with a solid to liquid ratio equal to 4/1, pH of 1.04, and H2SO4 concentration of 72.5 wt. %. High yields were also obtained for zinc recovery from the waste stream (100% for two series with solid to liquid ratio 4/5, pH of 0.80; H2SO4concentration of 37.2 wt. %, and solid to liquid ratio 1/2; pH of 1.01; H2SO4 concentration of 27.3 wt. %). Besides, the quantitative and qualitative analysis of Zn-C and Zn-Mn batteries introduced to the Polish market and waste generated in the years 2010-2018 has been presented.

6

Trace muscovite dissolution separation from vein quartz by elevated temperature and pressure acid leaching using sulphuric acid and ammonia chloride solutions

Lin M., Pei Z.-Y., Lei S.-M., Liu Y.-Y., Xia Z.-J., Xie F.-X.

Physicochemical Problems of Mineral Processing

|

2018

|

Vol. 54, iss. 2

448--458

EN

Effects of sulphuric acid and ammonia chloride on muscovite dissolution were studied in acid leaching of vein quartz under elevated temperature and pressure. The leaching processes have been studied in detail by analyzing sources of impurity minerals, optimizing leaching process, analyzing leaching kinetics of Al in muscovite and charactering leaching mechanism of muscovite. The results showed that elements of Al and K mainly occurred in muscovite, and 98.10% or more of muscovite could be removed by acid leaching, while the process had limited influence on the particle size of quartz sand. Leaching of Al in the quartz ore was mainly controlled by chemical reaction. A calcination process and ammonia chloride were used for reducing chemical reaction resistance by damaging crystal structure of muscovite and providing stable acid leaching environment. Combined with the calcination process, muscovite, as a main gangue mineral, was effectively extracted during acid leaching of vein quartz at elevated temperature and pressure.

7

Calcination of Aluminum Chloride Hexahydrate (ACH) for Alumina Production: Implications for Alumina Extraction from Aluminum Rich Fly Ash (ARFA)

Zhao L.

Archives of Metallurgy and Materials

|

2018

|

Vol. 63, iss. 1

235--240

EN

Alumina rich fly ash (ARFA) has been regarded as the alternative to bauxite in China. Hydrochloric acid process could be favored for alumina extraction, necessitating calcination of aluminum chloride hexahydate (ACH). In this work, the TGA/DSC results of ACH were used to suggest calcination procedures. Two-step calcinations of 200-1000°C and 350-1000°C did not increase the surface area of alumina, by comparison with one step 1000°C calcination, and a slow heating rate could improve the surface area. Calcination temperature was increased from 950 to 1250°C in a step of 50°C, and XRD, XRF, BET and gas pycnometer were used to characterize the alumina from calcinated ACH. Consistent results were obtained by these different techniques, and two groups of impurities were identified and related to alumina purity and surface area. By comparison with clays, it was suggested to remove impurities such as MgO, Na2 O, K2 O, P2 O5 and SO3 in hydrochloric acid leaching of ARFA.

8

A comparison of uranium recovery from low-grade ore by bioleaching and acid leaching

Szolucha M. M., Chmielewski A. G.

Physicochemical Problems of Mineral Processing

|

2017

|

Vol. 53, iss. 1

136--149

EN

The objective of this work was to compare the bioleaching with the acid leaching of uranium under similar process conditions within 65 days. The low-grade uranium ore used in the experiments was collected from Radoniow’s ‘small’ dump, Poland. Bioleaching and acid leaching studies were carried out in identical columns. The isolated bacterial consortium from the Radoniow’s mine was used for the bioleaching process. A solution of sulphuric acid and H2O2 as oxidizing agent was used for the acid leaching. The extraction of uranium under acid leaching conditions reached maximum of 64±13 % w/w after 31 days. The bioleaching of uranium achieved a maximum extraction of 75±15 % w/w after 55 days. In this study an attempt was made to demonstrate the relationship between the shrinking-core model and the experimental data by plotting the fractional conversion of uranium against time.

9

Wydzielanie związków żelaza z roztworu po ługowaniu odpadów poflotacyjnych Zn-Pb

Siedlecka E., Sobik-Szołtysek J.

Inżynieria i Ochrona Środowiska

|

2017

|

T. 20, nr 2

263--276

EN

Iron is usually present in the leaching solutions and its elimination is a major problem in hydrometallurgy. The recovery of iron from such solutions is usually carried out by precipitation as jarosite, goethite or hematite. Together with the iron other undesirable metals, mainly Zn, Mg, Pb are precipitated. The impact of the following parameters: temperature, time, type and dose of oxidant on selective separation the iron compounds from the leaching solution of Zn-Pb post-flotation tailings were investigated. The leaching solution was obtained in the process of dynamic neutralization the accumulator electrolyte with the Zn-Pb flotation tailings and separation of the precipitate from the solution. Using the set conditions of iron compounds precipitation from the leaching solution, the post-processed solutions were obtained in which the content of Mg, Zn, Fe were analyzed. It was found that the process of iron compounds precipitation causes co-precipitation of the accompanying metals that contaminate the resulting precipitates. The coprecipitation of magnesium, together with iron compounds is particularly disadvantageous process results in a reduced yield of metal in the final product. In order to minimize these losses, the oxidizing precipitation of iron from the leach solution in the form of goethite was carried out. This led to significant loss of Mg+2 ions from the solution in an amount of 0.24% positively influencing technological process of magnesium sulphate recovery from the waste. The goethite precipitate formed in a simple single stage process is a commercial product or an intermediate product (after ignition) for the preparation of a red pigment.

PL

Żelazo jest często obecne w roztworach po ługowaniu, a jego eliminacja jest głównym problemem w procesach hydrometalurgicznych. Odzysk żelaza z takich roztworów polega najczęściej na jego wydzieleniu w postaci jarosytu, getytu lub hematytu. Wraz z żelazem wytrącają się inne niepożądane metale, głównie Zn, Mg, Pb i inne. W pracy zbadano wpływ takich parametrów, jak temperatura, czas, typ i dawka utleniacza na selektywne wydzielanie związków żelaza z roztworu po ługowaniu odpadów poflotacyjnych Zn-Pb. Roztwór po ługowaniu pozyskano w procesie dynamicznej neutralizacji elektrolitu akumulatorowego odpadem poflotacyjnym i oddzieleniu osadu od roztworu. Stosując ustalone warunki wydzielania związków żelaza z roztworu po ługowaniu, otrzymano roztwory poprocesowe, w których oznaczono zawartość metali: Mg, Zn, Fe. Stwierdzono, iż proces wydzielania związków żelaza, w zależności od warunków, powoduje współstrącanie się towarzyszących metali, które zanieczyszczają powstałe osady. Szczególnie niekorzystnym procesem jest współstrącanie się magnezu wraz ze związkami żelaza powodujące zmniejszenie uzysku metalu w produkcie końcowym. W celu zminimalizowania tych strat przeprowadzono strącanie utleniające żelaza z roztworu po ługowaniu w postaci getytu, uzyskując nieznaczne straty jonów Mg+2 z roztworu w ilości 0,24%, co jest bardzo korzystne dla procesu technologicznego pozyskiwania siarczanu magnezu z odpadów. Wydzielony osad getytu w prostym procesie jednostopniowym stanowi produkt handlowy, a po wyprażeniu - półprodukt do otrzymywania pigmentu czerwonego.

10

Long-term planning for open pits for mining sulphide-oxide ores in order to achieve maximum profit

Krzanovic D., Conic V., Stevanovic D., Kolonja B., Vaduveskovic J.

Archives of Mining Sciences

|

2017

|

Vol. 62, no. 4

807--824

EN

Profitable exploitation of mineralised material from the earth’s crust is a complex and difficult task that depends on a comprehensive planning process. Answering the question of how to plan production depends on the geometry of the deposit, as well as the concentration, distribution, and type of minerals in it. The complex nature of mineral deposits largely determines the method of exploitation and profitability of mining operations. In addition to unit operating costs and metal prices, the optimal recovery of and achievement of maximum profit from deposits of sulphide-oxide ores also depend, to a significant extent, on the level of technological recovery achieved in the ore processing procedure. Therefore, in defining a long-term development strategy for open pits, special attention must be paid to the selection of an optimal procedure for ore processing in order to achieve the main objective: maximising the Net Present Value (NPV). The effect of using two different processes, flotation processing and hydrometallurgical methods (bioleaching acid leaching), on determining the ultimate pit is shown in the case of the Kraku Bugaresku-Cementacija sulphide-oxide ore deposit in eastern Serbia. Analysis shows that the application of hydrometallurgical methods of processing sulphide-oxide ore achieved an increase in NPV of 20.42%.

PL

Przynosząca zyski eksploatacja kopalin wydobywanych ze skorupy ziemskiej jest zadaniem złożonym i trudnym, wymagającym całościowego planowania. Aby określić w jaki sposób zaplanować prace wydobywcze, należy uwzględnić geometrię złoża, a także rozkład, koncentrację i rodzaj zawartych w złożu minerałów. Złożony charakter złóż minerałów w dużej mierze determinuje wybór metod wydobycia oraz poziom zysków. Obok jednostkowych kosztów produkcji oraz cen metali, optymalna eksploatacja złóż rud siarczkowych i osiągniecie maksymalnych zysków w dużej mierze zależą także od zastosowanych technologii uzyskiwania metalu z rud. Przy definiowaniu długoterminowej strategii wydobycia rud w kopalni odkrywkowej uwzględnić także należy wybór optymalnej metody obróbki rud w celu uzyskania założonego celu: maksymalizacji wartości bieżącej netto (NPV – Net Present Value). Wykorzystanie dwóch procesów: flotacji oraz metod hydro-metalurgicznych (bio-wypłukiwanie, ługowanie) przedstawiono dla rozważanego przypadku kopalni odkrywkowej rudy siarczkowej eksploatującej złoże w regionie Kraku-Bugaresku-Cementacija we wschodniej Serbii. Analizy wskazały, że zastosowanie metod hydro-metalurgicznych zapewnia wzrost wartości bieżącej netto o 20.42%.

11

Odzysk niklu, kadmu i kobaltu ze zużytych baterii

Kończyk J., Sobianowska-Turek A., Sobianowska K.

Prace Naukowe Akademii im. Jana Długosza w Częstochowie. Technika, Informatyka, Inżynieria Bezpieczeństwa

|

2016

|

T. 4

233-246

PL

W pracy zaproponowano czteroetapowy proces odzysku niklu, kadmu i kobaltu ze zużytych baterii niklowo-kadmowych (Ni-Cd) oraz niklowo-wodorkowych (Ni-MH) obejmujący obróbkę mechaniczną, kwaśne ługowanie odpowiednio przygotowanych odpadów bateryjnych, ekstrakcję rozpuszczalnikową badanych metali przy użyciu tetratiofosforylowanego rezorcyn[4]arenu oraz reekstrakcję metali do fazy wodnej. Ponadto, w celu optymalizacji procesu, określono wpływ wybranych parametrów, takich jak: temperatura początkowa i czas prowadzenia ługowania, rodzaj kwasu mineralnego oraz pH fazy wodnej i stężenie ekstrahenta na wydajność i selektywność odzysku badanych metali.

EN

Presented work describes four-step recovery process of nickel, cadmium and cobalt from Ni-Cd and Ni-MH batteries. The process consists of mechanical treatment, acid leaching, solvent extraction with the use of tetratiophosphorylated resorcin[4]arene and reextraction of the metal ions to aqueous phase. Additionally, in order to optimize the process, effect of some parameters, such as temperature and duration time of the leaching, the type of mineral acid, pH of aqueous phase and extractant concentration on efficiency and selectivity of metal recovery was determined.

12

Assessing influence of hydrochloric acid leaching on structural changes and bleaching performance of Nigerian clay from Udi

Ajemba R. O., Onukwuli O. D.

Physicochemical Problems of Mineral Processing

|

2014

|

Vol. 50, iss. 1

349--358

EN

Clay from Udi in Nigeria was mined, ground, and acid-leached at different concentrations of hydrochloric acid to produce adsorbents of varying properties. The raw and acid-leached samples were characterized using x-ray fluorescence (XRF) and Fourier transforms infra-red spectroscopy (FTIR) to examine the structural modifications in the clay as a result of acid-leaching. The analysis showed that the acid-leaching process caused several modifications of the clay samples. The surface area, Si/[Al + Fe + Mg] ratio, adsorption capacity were found to have increased in the acid-leached samples. The acid-leached samples were tested in order to ascertain their performance in bleaching palm oil and it was observed that the bleaching efficiency increased from 29.8% to 66.7%. The acid-leached sample prepared with 7M hydrochloric acid yielded an adsorbent that was efficient in bleaching palm oil under the experimental conditions. The isotherm analysis showed that the bleaching process followed the Freundlich equation.

13

Iron removing from titanium slag for synthetic rutile production

Mehdilo A., Irannajad M.

Physicochemical Problems of Mineral Processing

|

2012

|

Vol. 48, iss. 2

425-439

EN

Leaching with sulfuric and hydrochloric acids for upgrading titanium slag obtained from the Qara-aghaj ilmenite concentrate to a high grade titanium dioxide (TiO2) was studied. The titanium slag containing 72.7% TiO2 and 7.8% Fe2O3 was leached at varying solid/liquid (S/L) ratio, particle size, leaching time and acid concentration. The optimum amount of S/L ratio, particle size, acid concentration and leaching time using both acids were determined as 1:4, -100 µm, 8% and 2 h. Under optimum conditions, by using sulfuric acid, a titanium dioxide concentrate with 86.8% TiO2 and 1.87% Fe2O3 was produced, while employing hydrochloric acid resulted in a concentrate containing 91% TiO2 and 0.61% Fe2O3. The titanium dioxide concentrate prepared with hydrochloric acid, having acicular texture and by means of elongated separate particles; has less impurities than the one produced by sulfuric acid. The results demonstrate that hydrochloric acid dissolution of titanium slag and removing some impurities such as SiO2 and MgO provide a product with good quality is prepared which is suitable as raw material for TiO2 pigment production through the chloride process.

14

Thermal and acid treatment of diatom frustules

Gulturk E, Guden M

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 46, nr 2

196--203

EN

Purpose: Diatoms, belonging to Bacilariophyta family, are single-celled microscopic (1-100 micron) plants living in aquatic environment. The diatom cell is protected inside a shell (frustule) constructed from amorphous nano-silica particles. It is proposed that the frustules and purified silica powders obtained from frustules can be used to reinforce composites. In this study, microstructural properties of two diatom frustules were determined and different methods were investigated for silica powder processing from diatom frustules. Design/methodology/approach: Natural (ND) and calcined (CD) diatom frustules were used in this study. The chemical and microscopic properties of the diatom frustules were determined using Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectrometry (FTIR) and energy dispersive X-Ray Florescence spectrometer (XRF). Two different processing routes were applied to process silica powder from diatom frustules. These included (i) leaching the frustules directly in HF, (ii) incorporating thermally treated frustules in to the liquid nitrogen. Findings: At increasing HF concentrations, the variety of shapes, nanopores and open voids were seen on the surface of frustules as silica particles were removed from the surface. SEM micrograph results showed that HF significantly etched inside the existing pore structure of the diatom frustules. HF concentration was found more effective in mass loss than the leaching time. Thermal treatment induced several cracks propagated between macro pores and nanopores of the frustules. Practical implications: Results show that thermal and acid treatments were not effective for obtaining silica powder from frustules. Ball milling can be used for silica powder processing from frustules in the further study. Originality/value: In this paper, the microstructural properties of ND and CD frustules were determined. The effect of thermal and acid treatment on frustules was investigated with SEM.

15

The optimization of low-magnesium zinc concentrate production process

Jarosiński A., Fela K.

Polish Journal of Chemical Technology

|

2009

|

Vol. 11, nr 1

20-23

EN

In this paper the result of the study on chemical leaching of zinc concentrate with H2SO4 solution was presented. The object of this work was to assess the effect of some parameters such as acid concentration, the leaching agent amount /stoichiometry amount or excess of acid were applied/, reaction time and temperature on the process. The investigation was performed as a active experiment according to Hartley's plan. The process optimisation procedure was based on the fuzzy logic system. Mainly, the parameters such as magnesium leaching efficiency and zinc losses were taken into account. It was stated that the highest magnesium leaching efficiency of 77.8% with low Zn-losses was reached when H2SO4 solution concentration was 2.5% for 20%-excess of acid, at temperature 25°C and process time of 1 hour.

16

Utilization of the waste products of the copper industry of application of post-rafinement electrolites

Nowakowski J., Bukiej W.

Metallurgy and Foundry Engineering

|

2002

|

Vol. 28, no. 1

65-71

EN

The authors present their investigation of the possibility of applying waste post-refinement electrolytes after preliminary copper elimination to etching of solid waste materials containing heavy metals and increased amount of arsen. The processes of dissolving these materials in the electrolyte, neutralisation of the obtained solution and thermal decomposition of the obtained pulp were carried out. The result of these processes was the separation of heavy metals (sediment) and arsen (solution).

PL

Praca przedstawia badania nad możliwością zastosowania odpadowych elektrolitów porafinacyjnych - wstępnie odmiedziowanych, do ługowania kwaśnego stałych materiałów odpadowych przemysłu miedziowego, zawierających metale ciężkie i podwyższony arsen. Wybrano materiały pyliste - pochodzące z jednego węzła technologicznego, które zawierały jako główne składniki: miedź, cynk, arsen oraz pewne ilości ołowiu i żelaza. Materiały te poddano rozpuszczeniu w odpadowym elektrolicie porafinacyjnym, następnie otrzymany roztwór poddano dokwaszeniu, by zwiększyć w nim zawartość miedzi i arsenu, a otrzymany osad zawierał głównie siarczan ołowiu. Otrzymany roztwór poddano neutralizacji i termicznemu rozkładowi, by rozdzielić miedź i nikiel od arsenu. W wyniku tych procesów otrzymano roztwór - o podwyższonej zawartości arsenu i osad, składający się z miedzi i niklu w postaci utlenionej. Na postawie przeprowadzonych badań zaproponowano schemat technologiczny przerobu materiałów odpadowych, zawierających metale ciężkie i podwyższony arsen.