Basic Sulfate Research Articles

Study of Copper and Zinc Extraction from Underspoil Water

The subject of study was the Safyanovskaya Med company’s acidic underspoil water containing 0.17 g/liter of copper and 1.8 g/liter of zinc (pH 2.8–2.9). The goal was to study and develop a technology of cleaning water of impurities (copper, zinc, aluminum, iron, manganese), accompanied by extraction of copper and zinc in the form of commercial products. Copper extraction by cementation with metallic iron was studied. It was shown that this method could allow extracting 94–95% copper into a concentrate. The role of resolution processes of precipitated copper in cementation was established. To reduce the consumption of iron and to improve the quality of precipitated copper, it is proposed to carry out cementation in a washbox. The copper content in the concentrate was 27–28%, while the specific consumption of iron was 7.0–7.5 kg/kg of copper. During the studies of material composition of copper precipitate, the formation of cuprospinel, goethite, and bassanite phases and the precipitation of basic aluminum sulfates were detected. The extraction of zinc from the solution after copper removal was studied by precipitation with sodium sulfide. As a result, a concentrate was obtained with a zinc content of 49.6–50.9% with extraction of 99%. The process regularities for zinc concentrate dehydration were studied. By optimizing the crystallization conditions of the precipitate, a minimum final cake moisture content of 40–42% was reached. A process flow diagram for acidic underspoil water, including copper cementation and the precipitation of zinc sulfide, was developed. According to this diagram, the mother solution from zinc precipitation should be treated with lime until the pH reaches 10–10.5, followed by slurry settling. As a result, clean water of the following composition is obtained, mg/liter: 0.05 zinc, 0.01 copper, 0.02 aluminum, < 0.02 iron, 0.05 manganese. These values correspond to the quality of drinking water according to GOST R 51232-98.

Predominance Area Diagrams Bounding the Cu-As-S-O System’s 3D Predominance Diagram at 900 K (627 °C)

The two-dimensional predominance area (Kellogg) diagram (PAD) surfaces bounding the three-dimensional Cu-As-S-O system were constructed at 900 K. The computations employed gases As4O6(g), O2(g), and SO2(g) as the independent coordinate species to generate diagrams of As4O6(g) − O2(g),O2(g) − SO2(g), and As4O6(g) − SO2(g), while the third gas (As4O6, O2, or SO2) was fixed. The results indicate that there is no shared boundary between enargite (Cu3AsS4) and copper sulfate (CuSO4); however, at $$ {\mathrm{P}}_{{\mathrm{O}}_2} {10}^{-4} $$ atm, CuSO4 is the stable phase at 900 K. The chemical driving force for oxidation of intermediate phases between enargite and copper sulfate is substantial except for basic sulfate (CuO · CuSO4).

New extraction technique of zirconium and hafnium from zircon mineral

Zirconium and hafnium compounds are widely used in today’s technology. Zirconium or hafnium carbides and borides are high temperature ceramics.The present study concerns primarily with optimizing the extraction of zirconium and hafnium from their naturally occurring mineral, zircon, via a wet chemical process. First , zircon heated with molten sodium hydroxide to form zironate and silicate frit. Simple separation technique of sodium silicate from the zirconate and hafnate sodium was then applied to obtain a silicate-free frit, then the extraction of the zirconium ( IV ) and hafnium ( IV ) basic sulfates from their oxychloride solution leaving almost all other ions soluble in the mother liquor was achieved by adjusting the pH value. The precipitate of zirconium ( IV ) and hafnium ( IV ) basic sulfates was dried, weighed, analyzed and percent of the zirconium and hafnium extracted were found to be 97 % of their original concentration.

Recycling of (Soaking, Deliming and Retannage) Solutions in Amatong Tannery in the Sudan

&#x0D; &#x0D; &#x0D; Tanneries use much of chemicals such as sodium sulphide ,calcium hydroxide, ammonium sulphate, acids, basic chromium sulphate bactericide and fungicide. All these substances contribute to the environment pollution, although biological and chemical treatment methods are required, but still these methods are not effective enough to reduce pollution to the international standard level required. This pollution problem has to be solved completely via recycling through all wet processes from soaking to retannage.In this study the spent solutions were recycled for soaking, deliming and retannage processes many times with addition of makeup of chemicals and water ,that normally used , The produced crust quality was tested and the results were found to be satisfactory.&#x0D; &#x0D; &#x0D;

Recycling of (Soaking, Deliming and Retannage) Solutions in Amatong Tannery in the Sudan

&#x0D; &#x0D; &#x0D; Tanneries use much of chemicals such as sodium sulphide ,calcium hydroxide, ammonium sulphate, acids, basic chromium sulphate bactericide and fungicide. All these substances contribute to the environment pollution, although biological and chemical treatment methods are required, but still these methods are not effective enough to reduce pollution to the international standard level required. This pollution problem has to be solved completely via recycling through all wet processes from soaking to retannage.In this study the spent solutions were recycled for soaking, deliming and retannage processes many times with addition of makeup of chemicals and water ,that normally used , The produced crust quality was tested and the results were found to be satisfactory.&#x0D; &#x0D; &#x0D;

Patagonian salt marsh soils and oxidizable pedogenic pyrite: solid phases controlling aluminum and iron contents in acidic soil solutions

The sulfidic materials present in salt marshes could be oxidized forming sulfuric acid, increasing the toxic levels of both Al and Fe available to plants. The objectives of this study were: (a) to evaluate the mechanism of acid generation from the oxidation of sulfidic materials, and (b) to predict solid phases governing the dissolved Fe and Al concentrations in soils at low pH. The study was conducted in 14 soil profiles associated to eight salt marshes situated along the Atlantic coast of Patagonia. The potential acidity was estimated by the peroxide-oxidizable sulfuric acidity method (POSA). To predict the availability of Fe and Al at low pH, the solid phase equilibrium that governs the solubility of these elements through ion activity of the products was determined. The scanning electron microscopy analysis in sulfidic materials reveals the occurrence of framboidal pyrite. The relative variability of POSA at low pH values may indicate retention of sulfates by Al and Fe hydroxides, producing the formation of basic sulfates of iron and aluminum. At pH > 5.5, Fe2+ and Al3+ activities show an equilibrium with amorphous oxy-hydroxides of Fe(OH)3 and gibbsite, respectively. As the pH begins to decline below 5.5, Fe2+ and Al3+ activities show an equilibrium with respect to soil–Fe(OH)3 and Al(OH)3 amorphous, respectively. While for more acidic conditions, the solid phase in predicting both Fe2+ and Al3+ activities was basic iron sulfate and jurbanite. The acidic soil solutions with pH < 3, Fe2+ and SO42− activities show an equilibrium with goethite and melanterite, respectively. As a consequence of acid generation, phosphorus adsorption by aluminum and iron oxide minerals was detected.

Recycling the industrial waste ZnFe2O4 from hot-dip galvanization sludge

In this study, the goal was to find lower temperature for separating the Zn and Fe content of ZnFe2O4 by sulfation reaction than previously achieved and to study the various reaction steps of sulfation. Hence, the reaction of ZnFe2O4 with Mohr’s salt containing iron(II), i.e., (NH4)2Fe(SO4)2·6H2O, and ammonium iron alum containing Fe(III), i.e., NH4Fe(SO4)2·12H2O, was studied. At first, the thermal decomposition of precursor salts in air was studied by TG/DTA-MS to find the proper temperature for sulfation. Then ZnFe2SO4/precursor salt mixtures with ratios 1:2 and 1:5 were prepared and annealed at 400, 425 and 450 °C. The solubility of the products obtained at different annealing temperatures in water (e.g., ZnSO4, FeSO4, Fe2(SO4)3) and in HCl (Fe2O3, ZnO, Fex(OH)ySO4, Znv(OH)wSO4 basic sulfates) was studied. The morphology and structure of the starting materials was investigated by SEM, XRD and FTIR, the crystalline phases after each annealing and washing step were studied by XRD. The Fe in the starting materials and the products obtained at 425 °C was measured by Mössbauer. Based on the obtained results, it was demonstrated that the sulfation reaction with ammonium iron sulfates could be performed at lower temperatures than with iron sulfates. It was possible to detect the reaction intermediates and to obtain information about the reaction intermediates. With our sulfation reaction, depending on the reaction conditions, it is possible to obtain Fe2O3 as final product, but the Zn and Fe metals can be obtained also as sulfates. Our results open up further possibilities to recycle the ZnFe2O4 waste material.

Role of pH on the adsorption of xanthate and dithiophosphinate onto galena

ABSTRACTIn the concentrators of a Mexican mining company has been observed that the pH of the flotation has a significant effect on the galena recovery: the increase of pH from 7.5 to 9.5 in the Pb/Cu flotation circuit, resulted in a decrease of about 10% of lead recovery. In the present investigation, experimental models and techniques were developed to study the effect of pH on xanthate and di-isobutyl dithiophosphinate adsorption onto galena. The results obtained by UV / Vis spectroscopy showed that once galena surface has been slightly oxidised by the dissolved oxygen of the aqueous suspension, adsorption of both surfactants increases significantly, being adversely affected by the increase of pH from 5.5 to 9.5. Microflotation measurements performed for both surfactants support these findings. Thermodynamic simulation of the system suggests that the observed behaviour is due to the nature of the solid species formed on the galena surface at the particular pH: lead sulfate (PbSO4) under neutral and slightly acid conditions, and the basic sulfate (2PbO·PbSO4) under neutral and slightly alkaline conditions, as well as to their respective solubility. Infrared spectrometry confirmed the occurrence of sulfate onto galena particles, with a higher concentration for the acid pre-conditioning compared to the alkaline pre-conditioning.

Morphology‐Controllable Synthesis of Cubic‐Structured In2O3 Particles with Enhanced NO2 Gas Sensitivity

A hydrated basic sulfate precursor for In2O3 is facilely prepared from the mixed indium nitrate and ammonium sulfate solutions via means of single‐step hydrolysis precipitation at a relatively low synthetic temperature of ≈60 °C, which subsequently converts to an oxide powder via pyrolyzing. The morphologies of the precursor and oxide can be controlled via adjusting volume fractions of ethanol‐water solvents. The pure water solvent in the reaction system leads to a thick two‐dimension plate‐like precursor and its oxide generally retains the original shape, while the addition of ethanol up to the volume fraction of 75% in the mother liquor is able to effectively reduce the thickness of the plates to result in well‐dispersed oxide powder with round morphology via partial split, full collapse, and particle growth processes. The as‐prepared In2O3 gas sensors have rapid response and recovery time to trace NO2 and the In2O3 gas sensor derived from the well‐dispersed oxide powder has a rather higher sensitivity than the agglomerated one.

Sulfur Dioxide Desorption Characteristics of Basic Alkali Aluminum Sulfate Desulfurization Rich Liquid by Falling Film Evaporation with a Spring Tube

This paper presented a novel technology for the desorption of SO2 in the basic aluminum sulfate solution (BASS) by falling film evaporator with spring tube. The liquid film falling along the internal surface of the evaporation tube was heated by the steam outside. The desorption performances of the vertical single falling film evaporators with spring tube and smooth tube were comparatively investigated. The film distribution on the inner surface of the two tubes were also analyzed through visualization experiments. Compared with the smooth tube, the spring tube was found to be much better in heat transfer and mass transfer. Thus, analysis on the operating parameters for the desorption of SO2 was performed only in the spring tube. The results showed that the flow rate of BASS rich in SO2, heating steam temperature, vacuum of the system, and initial concentration of SO32– played important roles in the desorption performance.

Chemical–Mineralogical Systems That Are Able To Generate Nitrogen Compounds on Earth and Even Mars

The formation of nitrogen compounds by chemical fixing of atmospheric nitrogen in ambient conditions in only one technological step is of particular interest for the chemical industry and science. The effect is achieved by air bubbling through the reactor containing a cross-linked ionic polymer with strongly basic functional groups and sulfate solution of a trivalent metal. The lower the temperature of the reactor, the higher the yield production of nitrogen compounds. In the polymer phase, jarosite-type compound formation occurs that participates in the redox processes, followed by the partial destruction and synthesis of nitrogen compounds. The results from this work demonstrate that, under certain conditions, systems containing a strongly basic cross-linked polymer and solution of three valence metal sulfates (Fe3+, Ga3+, and others) are able to generate nitrogen-containing compounds, using atmospheric nitrogen. The spontaneous and uncontrolled processes of nitrogen compound generation could occur in n...

Characterisation of solid phases in the iron–sulphate–water system where silver is present

ABSTRACTA pressure oxidation (POX)-hot cure (HC)-lime boil (LB) process is used in industry to recover silver from refractory gold sulphide ores containing minerals such as pyrite and arsenopyrite. Pressure oxidation is used to oxidise minerals and liberate occluded gold particles. As such, iron goes into solution and under acidic and high-temperature conditions often precipitates as basic iron sulphate (BFS). BFS consumes excess lime during neutralisation before cyanidation. Therefore, a hot cure stage is required to re-dissolve BFS back into solution. BFS re-dissolution consumes acid and produces ferric sulphate. In the presence of silver, these conditions favour the slow formation of silver jarosite. Silver jarosite is refractory to cyanidation and must be broken down before cyanidation. This is done in the lime boil to produce a cyanide-soluble silver hydroxide. A study was conducted to investigate parameters that affect the precipitates that form in each stage of the POX-HC-LB process.

Mathematical modeling of ferrous sulfate oxidation in presence of air

In the present paper we studied the oxidation of ferrous sulfate salt with oxygen. ferric ammonium sulfate and ferrous sulfate were used to prepare standard solutions of Fe(III) and Fe(II) solutions. Oxidation experiments were carried out by mixing FeSO4·7 H2O in H2O. Air was supplied using a gas washing bottle in which air entered the bottle through the center tube, and exited into the bottom of the bottle. Samples were taken periodically and analyzed in the UV-Vis spectrophotometer. We consider that basic Fe(III) sulfate was one of the main compounds produced during the reaction and proposed a model to describe the process. We found solution to the differential equations that described the profile of FeSO4 and FwOHSO4 concentration in time and observed agreement between the experimental results and data predicted by the model. Moreover, we determined values of rate constants using the model and confirmed the determined values by means of experiments. This suggests that basic ferric sulfate was generated after aeration of ferrous sulfate solution.

Efficient removal of copper from wastewater by using mechanically activated calcium carbonate

Copper removal from aqueous solution is necessary from the stances of both environmental protection and copper resource recycling. It is important to develop a new chemical precipitation method suitable for removing copper particularly at low concentration as the case of waste mine water, with regards to the various problems related to the current precipitation methods by using strong alkalis or soluble sulfides. In this research, we studied a possible chemical precipitation of copper ions at concentration around 60 mg/L or lower by cogrinding copper sulfate in water with calcium carbonate (CaCO3) using wet stirred ball milling. With the aid of ball milling, copper precipitation as a basic sulfate (posnjakite: Cu4 (SO4) (OH)6·H2O) occurred at a very high copper removal rate of 99.76%, to reduce the residual copper concentration in the solution less than 0.5 mg/L, reaching the discharge limit, even with the addition amount of CaCO3 as a stoichiometric ratio of CaCO3/Cu2+at 1:1. It is more interesting to notice that, at the same conditions, other heavy metals such as Ni, Mn, Zn and Cd do not precipitate obviously just with CaCO3 addition at CaCO3/M2+at 1:1 so that the precipitate without the impurities can be processed as good source to recover copper. This newly proposed concept can be further developed to treat wastewaters with other metals to serve both purposes of environmental purification and resource recovery in a similar way.

SEPARATION OF ZIRCONIUM AND HAFNIUM WITH SIR METHOD’S (ADSORPTION AND DESORPTION ION EXCHANGE)

Precence of hafnium is more than 100 mg/kg making it impossible to use as cladding material in nuclear reactor, because of its high adsorption cross section thus inhibite the nuclear fission. The objective of this research is to separate Zr – Hf using SIR method that is by impregrnating extracts to resin. Extractants used are TBP and D2EHPA, resin used is XAD – 7, and feed used is Zirconium Basic Sulphate (ZBS). In this research is done variation compotition SIR, optimation process adsorption and desoprtion SIR and determintionof equation model in adsorption SIR. The result of this research is composition SIR the most effective for separation Zr – Hf is 5 : 5 for dry method’s and 7 : 3 for wet metode’s, model of equation for Zr nearly Langmuir model, model of equation for Hf nearly Freundlich model and adsorption result effenctively is comparation feed : SIR yaitu 10 mL : 1,5 g (1 : 1,5) with separation factor 30.12 ; separation efficiency Zr 31.47 % and separation efficiency Hf 42.06%.

Separation of copper from nickel in sulfate solutions by mechanochemical activation with CaCO3

Lime neutralization is widely used to precipitate heavy metals including copper and nickel from wastewater. Limestone (calcium carbonate: CaCO3) is too stable to be used directly for this purpose. Grinding of CaCO3 in the solutions of copper and nickel sulfate was conducted to raise its reactivity. During the mechanochemical activation, CaCO3 reacted with copper sulfate to form insoluble copper compounds as basic carbonate and basic sulfate. No reaction between CaCO3 and nickel sulfate occurred even with such activation. This new phenomenon allowed an easy separation of copper from nickel. Several parameters including grinding rotational speed, Cu to Ni ratio (Cu/Ni), solid to liquid ratio and Ca in CaCO3 to Cu ratio (Ca/Cu) were investigated to examine the effects on separation efficiency and to find out the conditions at which more than 99% of the copper (Cu(II)) ions were precipitated with more than 99% of the nickel (Ni(II)) ions remaining in the aqueous solution. Changes in phase composition by XRD analysis, solution pH and particle size of solid sample were investigated to understand the probable mechanism involved in the separation process, together with the comparisons in solubility of copper and nickel carbonates to that of CaCO3.

Reductive leaching of jarosites by Aeromonas hydrophila

The mineral industry has suffered in recent years two significant impacts: the raise on energy cost and more strict environmental regulations. In parallel to the above restrictions, the depletion of high grade mineral resources leads the mining industry to search for alternative processes to avoid the high energy consumption and exploit low grade mineral deposits. Jarosite is a common product in mining and industrial operations. This basic sulfate mineral incorporates several metals by substitution and the dissolution of jarosite by dissimilatory iron-reducing bacteria influences the mobility of many heavy metals present in the mineral structure.In this work, the anaerobic bioreduction of three ferric solids (a biogenic mixture of ammonium and potassium jarosites, synthetic silver jarosite and natural gossan ore from RioTinto, Spain) by an isolated strain of Aeromonas hydrophila has been investigated. The release of ferrous ion indicated that the microbial reduction of jarosite takes place using lactate as electron donor. This process was accompanied by the subsequent secondary mineralization, leading to the formation of various iron-bearing minerals such as siderite, vivianite or magnetite. In addition, the influence of chelating agents (citrate and EDTA) and humic substances’ analogue (AQDS) as electron shuttling molecule were studied. While the chelants increased iron reduction and dissolution rate, the humic substances had no effect in the process. These results suggest that direct contact between A. hydrophila and minerals is required for the reduction of Fe(III).

Raman and SEM‐EDX analyses of the ‘Royal Portal’ of Bordeaux Cathedral for the virtual restitution of the statuary polychromy

The chemical analysis of the remains of paintings from the Royal Portal of Bordeaux Cathedral was carried out byin situanalytical techniques and by laboratory techniques after sampling. Even though, nowadays, portable systems have a good performance and provide reliable results, in the present case, thein situapproach failed, and the analysis had to be carried out in the laboratory. The obtained results were used to propose a virtual restitution of the polychromy and to have an idea of how this portal was when it was built in the XIII century. During the analysis, the degradation process of pigment azurite was studied through the determined decay products, such as copper oxalate (moolooite) and copper basic sulfate (brochantite). This degradation seems to occur because of the presence of oxalic acid in the chemical system, as other calcium oxalates (weddellite) were identified as a degradation product of calcareous support. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Ammonium Alunite and Basic Aluminum Sulfate: Effect of Precipitant Agent

Ammonium bisulfite as a precipitating agent was used to synthesize basic aluminum sulfate (BAS) by homogeneous precipitation. Aluminum sulfate in aqueous solution was used as the raw material. High concentration of the precipitant agent promotes the formation of ammonium alunite, which was confirmed by XRD, TG/DTG and FTIR analysis. The ammonium alunite has less sulfate ions and more water than the BAS, and so, the ammonium alunite heat treated up to 1200°C produces 28 weight percent of Al2O3. In comparison the BAS generates 48 weight percent of Al2O3 as a final product. Homogeneous precipitation promotes the formation of amorphous spherical particles of basic aluminum sulfate and lamellar crystalline particles of ammonium alunite which were observed by field emission microscopy (FEM).

Influence of the concentration of fluorine ions and clayey particles on the efficiency of aluminum coagulants in defluorination of water

The paper has investigated the influence of the initial concentration of fluorine ions (2.0–8.5 mg/dm3) on the efficiency of sulfate (SA), basic sulfate (OSA 2.0) and basic aluminum chloride (5/6 OXA) in defluorination of water. It has been established that replacement of aluminum sulfate by its basic salts makes it possible not only to reduce consumption of the coagulant, but also provides a possibility to clean waters polluted with fluorine ions by 27–35% without additional introduction of alkaline agents. The paper has shown good promises in using OSA 2.0 for defluorination of low turbidity waters (underground sources), while 5/6 OXA—for water with relatively high contents of suspended impurities.