Copper Sulfite Research Articles

Study on Flotation Techniques of Tailings in Dachang Mining

For the characteristics of complex paragenetic relationship, the high oxidation rate of lead antimony zinc minerals and serious sliming, GZ was used as activator and depressor, and GC was used as collector. In this study, we recover lead, antimony and zinc from tailings in Dachang mining efficiently without using copper sulfite as activator.

SU-E-T-192: Spatial Accuracy Considerations in the Development of a Gamma Knife Quality Assurance Program

Purpose: Spatial accuracy in a Gamma Knife SRStreatment plan is of utmost importance because of the single fraction high doses of ionizing radiation intended to be delivered to small volumes often times at close proximity to critical brain structures. Methods: Leksell‐Gamma Knife head frames and associated fiducial marker box attached to a phantom, as well as the MRI scanner were studied in this regard. Three phantoms with known geometrical accuracy were scanned. These included the ACR MRI accreditation phantom, GEMRI standard calibration phantom, and a specifically designed MRI phantom. The latter phantom consists of known size and positional coordinates of structures including a cone, cube, cylinder, and sphere. Observed measurements were made using a GE 1.5 tesla MRI scanner. Scanning was done following our standard protocol, i.e. T1 imaging, 512×512 pixels, 28×28 cm fov, and 1.5 mm slice thickness with no gap. All data was analyzed after being dicom transmitted to our Gamma Knife Treatment Planning computer. Results: We will show that over many applications of the head frame to patients, warping of the head frame can and does occur. Fiducial marker boxes are unlikely to warp or change the parameters of the copper sulfite tracks. The MRI scanner remains spatially accurate as long as a gradient field test is done routinely and attention is closely paid to the head coil and its associated small field gradient. This is generally accomplished during routine PMI by the manufacturer. Conclusions: Head frame alignment parameters dictate where the fiducial markers are actually found. If the fiducial marker parameters measured do not agree with the known position of the fiducial markers as stored in the treatment planning computer errors occur in the “Leksell” coordinate frame space. Clues will be provided indicating that the head frame has warped out of allowed tolerances.

Upgrading of a chalcopyrite concentrate by reaction with copper(II) and sulfite – Unexpected formation of Chevreul’s salt, Cu 2SO 3·CuSO 3·2H 2O

Recovery of aqueous copper(II) onto a chalcopyrite concentrate was shown to be rapid at 60 °C in the presence of S(IV), in this case sulfite. Surprisingly, rather than partial conversion of chalcopyrite to a copper sulfide such as chalcocite or covellite, copper was removed from solution by precipitation of a mixed-valence copper sulfite, Chevreul’s salt (Cu 2SO 3·CuSO 3·2H 2O). This has application as a way to increase the copper grade of chalcopyrite concentrates using the leachate from a Galvanox™ leach of flotation tailings, offering several advantages over similar processes employing an autoclave to effect copper precipitation.

PRECIPITATION CONDITIONS OF CHEVREUL'S SALT FROM SYNTHETIC AQUEOUS CuSO4 SOLUTIONS

In this study, synthetic aqueous CuSO4 solution was prepared at various concentrations. Chevreul's salt was precipitated by passing SO2 through these solutions. Chevreul's salt, a mixed valence copper sulfite, Cu2SO3·CuSO3·2H2O, was characterized by XRD and SEM. The effects of parameters such as initial solution concentration, SO2 feeding rate, reaction time, and initial solution pH on precipitation of Chevreul's salt were investigated. 2n factorial experimental design and orthogonal central composite design methods in the precipitation experiments were used. It was observed that the effective parameters on the precipitation of Chevreul's salt were initial solution concentration, SO2 feeding rate, and initial solution pH. The optimum conditions obtained for maximum copper precipitation were: initial solution concentration 1.14 M, SO2 feeding rate 329.35 L.h.−1, reaction time 25 min, and initial solution pH 8.5. Constant parameters chosen at the initial stage of the reaction were: temperature 62°C, stirring speed 600 rpm, and reaction pH 3 (Çalban et al., 2006). Under these optimum conditions, the percentage of precipitated copper from synthetic aqueous CuSO4 solutions was 99.95.

Statistical modeling of Chevreul's salt recovery from leach solutions containing copper

In this study, oxidized copper ore was dissolved under optimum conditions [temperature 14 °C, average particle size 2.8 mm, stirring speed 500 rpm, ammonia concentration 2.824 mol L −1, ammonium sulphate concentration 0.236 mol L −1, solid-to-liquid ratio 0.167 g mL −1, leaching time 2 h] in an aqueous NH 3-(NH 4) 2SO 4 solution [T. Çalban, S. Çolak, M. Yeşilyurt, Optimization of leaching of copper from oxidized copper ore in NH 3-(NH 4) 2SO 4 medium, Chem. Eng. Commun., in press]. Chevreul's salt was precipitated by passing SO 2 from these leach solutions. Chevreul's salt, a mixed valence copper sulfite Cu 2SO 3·CuSO 3·2H 2O, was characterized by XRD and SEM. The effects of parameters, such as temperature, pH, stirring speed and reaction time, were investigated on precipitation of Chevreul's salt. 2 n factorial experimental design and orthogonal central composite design methods in the precipitation experiments were used. It was observed that the most effective parameters on the precipitation of Chevreul's salt were temperature, stirring speed and reaction time. The optimum conditions established for maximum copper precipitation were: temperature 62 °C, pH 3, stirring speed 600 rpm, reaction time 12 min. Fixed parameters chosen at the initial stage of the reaction were: SO 2 flow rate 358 L h −1, concentration of CuSO 4 solution 7.383 g Cu L −1. Under these optimum conditions, the percentage of copper precipitated from leach solution was 99.92.

Anodic behaviour of alkaline solutions containing copper cyanide and sulfite on the graphite anode

Sulfite may be added to copper cyanide solutions to reduce cyanide oxidation at the anode during copper electrowinning. Anodic sulfite oxidation is enhanced in the presence of copper cyanide. Sulfite also suppresses the oxidation of copper cyanide. The effect of sulfite on the oxidation of copper cyanide decreases with increasing mole ratio of cyanide to copper. This is related to the shift in the discharged species from Cu(CN)32− to Cu(CN)43− with increasing mole ratio of cyanide to copper. Sulfite is oxidized to sulfate. At [Cu+] = around 1 M, CN:Cu = 3.0–3.2, [OH−] = 0.05–0.25 M, [SO32−] = 0.4–0.6 M and the temperature = 50–60 °C, the anodic current efficiency of sulfite reached 80–90%. With further increase in sulfite concentration beyond 0.6 M, the current efficiency of sulfite oxidation will not be increased significantly. Further increase in CN:Cu mole ratio will result in decrease in the anodic current efficiency.

Composition and stability of a polynuclear copper sulfite complex

Conditions for the formation of a polynuclear copper sulfite complex were studied by spectrophotometry, conductometry, and chemical analysis. The composition of the forming sulfites was determined, and the equilibrium constant of formation of the polynuclear copper sulfite complex and its dissociation constant were calculated.

Multianalytical in situ investigation of the initial atmospheric corrosion of bronze

Atomic force microscopy (AFM) and infrared reflection absorption spectroscopy (IRAS) were used for in situ investigations of the initial atmospheric corrosion of bronze. In addition ex situ XPS investigations were carried out on the samples before and after the exposure, as well as on the sputtered bronze sample. Investigations were carried out in synthetic air with 80% relative humidity (RH) and synthetic air with 80% RH with 250 ppb SO 2. At 80% RH, small features covering the surface were observed with AFM, whereas IRAS detected that more water is adsorbed on the bronze sample surface compared to pure copper. Large features on top of smaller features were observed with AFM on the bronze surface exposed to SO 2-containing humidified air. These large features were identified as copper sulfite. Furthermore, cuprous oxide was detected approximately 500 min after the introduction of SO 2. This fact and the XPS results indicate the formation of a protective lead oxide layer already during the preparation of the sample, which is destroyed by the SO 2-containing environment and leads to the formation of cuprous oxide and copper sulfite.

Anodic Dissolution of NiS in Sulfite Electrolytes

Electrochemical behavior of nickel sulfide in weakly acidic, ammonia electrolytes containingsulfite ions and also in copper sulfite electrolyte stabilized by EDTA was studied.

Spectroscopic and magnetic properties of Chevreul’s salt, a mixed valence copper sulfite Cu 3(SO 3) 2·2H 2O

Chevreul’s salt, a mixed valence copper sulfite Cu 3(SO 3) 2·2H 2O, was synthesized by a reaction between CuSO 4 and NaHSO 3, and characterized by X-ray photoelectron spectroscopy, magnetic susceptibility, EPR and electronic spectroscopy. These magnetic and spectroscopic studies consistently proved the validity of the formulation (Cu +) 2SO 3Cu 2+SO 3(H 2O) 2. Between Cu + and Cu 2+ ions an intervalence transition occurs with an energy of 23 500 cm −1.

Nitrile Metallurgical Process for Copper Concentrates

Economic, regulatory, and sociological factors have spurred the search for a copper production technology capable of providing high-purity copper from a variety of sources with low-unit capital, energy, and labor costs while meeting increasingly stringent ecological requirements. Nitrile copper-refining chemistry can be combined with other production operations to address these needs. Roasting concentrates results in a leachable calcine and SO2 gas which is absorbed to make a sulfite liquor and a cleaned gas. The sulfite liquor and calcine leach liquor are mixed to yield precipitated copper sulfite. The sulfur is removed as gypsum. A cupricl acetonitrile liquor converts the solid copper sulfite to a cuprous/ nitrile liquor which is disproportionated to produce the recycled cupric/ acetonitrile liquor and a pure-copper metal product. The roast/ leach/sulfite/ nitrile copper concentrate process is estimated to require 55% less energy and 30% less capital than modern pyrometallurgical methods.

Organic Sulfides and Polysulfides. I. Desulfurization Reactions

Abstract Mercury, copper, potassium cyanide and sodium sulfite were found to desulfurize organic polysulfides. In the p,p′-ditolyl and in the dibenzyl series, the di-, tri- and tetrasulfides gave disulfide by desulfurization. On the other hand, in the case of diglycolic acids, di-, tri- and tetrasulfides gave monosulfides. The sulfide, which has high polarity in its radical, is easily desulfurized. The relative ease of desulfurization is—diglycolic acid > dibenzyl > p,p′-tolyl. In the same series, the higher the sulfur content, the more unstable it seems to be. Mercury is more reactive with sulfides than is copper.