Showing papers on "Sodium sulfite published in 2018"
TL;DR: Sugarcane bagasse was pretreated with sodium carbonate, sodium sulfite, and sodium acetate to break down its structural recalcitrance and improve biogas and ethanol production, and Sodium acetate had less effect on biofuel production and was comparable with hydrothermal pretreatment.
65 citations
TL;DR: Using the HAM kinetic model established in this study, HAM half-lifes in drinking water distribution systems can be predicted on the basis of pH and residual chlorine concentration.
55 citations
TL;DR: Investigation of the degradation of 10 HAMs by sodium sulfite and the mechanism behind it suggest that S(IV) can be used to degrade brominated and iodinated HAMs in drinking water and therefore should not be added as a quenching agent before HAM analysis to accurately determine the HAM concentrations produced during water disinfection.
26 citations
TL;DR: In this article, it was established that sequential treatment of sulfate lignin with benzene, silver in dimethylformamide, aqueous sodium sulfite solution and perchloric acid + acetic anhydride mixture can reduce the total sulfur content a hundredfold.
Abstract: Kraft lignin is a product of the sulfate pulping process. It usually contains 2–3% total sulfur. Sulfur content acts as deterrent to lignin use in some areas. Sulfur-free lignins are more versatile and can be heat-treated without the release of foul-smelling sulfur compounds. These lignins are used to produce various low- and high-molecular products, as well as fuel. The existing soft desulfurization methods of kraft lignin allow reducing the total sulfur content, for example, fivefold by a method combining extraction of elemental sulfur, oxidation and reduction in sulfur compounds. Deeper desulfurization has earlier been achieved by catalytic hydrogenation, which is accompanied by depolymerization of lignin. In this paper, it was established that sequential treatment of sulfate lignin with benzene, silver in dimethylformamide, aqueous sodium sulfite solution and perchloric acid + acetic anhydride mixture can reduce the total sulfur content a hundredfold.
25 citations
28 Jun 2018
TL;DR: In this article, the utility of 1,3,5-trimethoxybenzene (TMB) as a quencher of free chlorine and free bromine was demonstrated.
Abstract: Sodium sulfite, sodium thiosulfate, and ascorbic acid are commonly used to quench free chlorine and free bromine in studies of disinfection byproducts (DBPs) in drinking water, wastewater, and recreational water. The reducing capabilities of these quenchers, however, can lead to the degradation of some redox-labile analytes. Ammonium chloride, another common quencher, converts free chlorine into monochloramine and is therefore inappropriate for analytes susceptible to chloramination. Herein, we demonstrate the utility of 1,3,5-trimethoxybenzene (TMB) as a quencher of free chlorine and free bromine. The reactivity of TMB toward free chlorine was characterized previously. The reactivity of TMB toward free bromine was quantified herein (kHOBr,TMB = 3.35 × 106 M−1 s−1) using competition kinetics. To explore the feasibility of TMB serving as a free halogen quencher for kinetic experiments, chlorination of 2,4-dichlorophenol, bromination of anisole, and chlorination and bromination of dimethenamid-P were examined. Although TMB does not react with free chlorine or free bromine as quickly as do some (but not all) traditional quenchers, there was generally no significant difference in the experimental rate constants with TMB (relative to thiosulfate) as the quencher. By monitoring the chlorination and bromination products of TMB, free halogen residuals in quenched samples were quantified. Furthermore, TMB did not affect the stabilities of DBPs (e.g., chloropicrin and bromoacetonitriles) that otherwise degraded in the presence of traditional quenchers. TMB could, therefore, be an appropriate quencher of free chlorine and free bromine in aqueous halogenation experiments involving redox-labile analytes and/or when selective quantification of residual free halogens is desired.
19 citations
TL;DR: In this paper, the main problem of the separation process from nickel mining using the ion exchange technique is the presence of iron, which precipitates in pH above 2.00 and causes coprecipitation of copper and cobalt.
Abstract: The main problem of the separation process from nickel mining using the ion exchange technique is the presence of iron, which precipitates in pH above 2.00 and causes coprecipitation of copper and cobalt. Chelating resins have the main advantage of being selected for a specific metal present in solution. Studies have been developed to increase the efficiency of metals recovery using chemical reduction and the ion exchange process to recover metals. The aim of this work was to use sodium sulfite as a reducing agent to convert Fe(III) to Fe(II). Chelating resins Lewatit® TP 207, selective for copper, and Lewatit® TP 220, selective for nickel and cobalt, were studied. Batch experiments were performed to study the effect of pH with and without sodium sulfite. Results indicated that the industrial process has increased efficiency when the reducing process is applied.
17 citations
TL;DR: The results revealed that the pH could be maintained at a relatively high level for an optimized pH-buffering effect when Na2SO3 was added before the reaction of Xyl-Phe and the conversion of N-(1-deoxy-d-xylulos-1-yl)-phenylalanine was successfully improved.
16 citations
TL;DR: In this article, the authors presented a novel lead dioxide reduction process which combined with flue-gas desulfurization technology to recover lead from lead-paste in the spent lead-acid batteries.
16 citations
TL;DR: In this paper, the authors demonstrate the importance of hydrothermal alkaline sulfite pretreatment of sugarcane bagasse in the delivery of fermentable sugars and demonstrate that the pretreatment conditions, namely sodium sulfite loads (50-100 wt), temperatures (140-160 °C) and reaction times (30-60 min), were tested according to the full factorial design of experiments.
Abstract: This work aims to demonstrate the importance of hydrothermal alkaline sulfite pretreatment of sugarcane bagasse in the delivery of fermentable sugars The pretreatment conditions, namely sodium sulfite loads (50–100 wt%), temperatures (140–160 °C) and reaction times (30–60 min), were tested according to the full factorial design of experiments The employed pretreatment was characterized by high lignin removal (43–77 wt%) and partial extraction of xylans (up to 250 wt%), mainly by cleavage of acetyl and arabinosyl groups After 72 h of enzymatic hydrolysis with 10 FPU (filter paper unit) cellulase and 10 CBU (cellobiose unit) β-glucosidase per g of pretreated bagasse, the conversion of the carbohydrate-enriched substrates was in the range of 51 to 80 mol% for cellulose and 45 to 71 mol% for xylans The best hydrothermal alkaline sulfite pretreatment conditions (100 wt% sulfite load, 150 °C and 45 min) were found to be highly efficient for the delivery of fermentable sugars with a yield as high as 404 ± 19 g for 100 g native bagasse
14 citations
TL;DR: In this paper, an effective way employing sodium sulfite for the stripping of iron(III) from Aliquat 336 with a high iron loading, which was generated in the iron removal from coal waste hydrochloric acid leach liquor, was reported.
14 citations
01 May 2018
TL;DR: In this paper, an imidazoline quaternary corrosion inhibitor suitable for oilfield was synthesized, which achieved an inhibition rate of 99.113% in hydrochloric acid.
Abstract: An imidazoline quaternary corrosion inhibitor suitable for oilfield was synthesized. Oleic acid, diethylene triamine, and quaternary ammonium reagents were used in the experiment. The dimethylbenzene was used as water carrying agent. Under the experimental conditions, the inhibition rate of the synthesized corrosion inhibitor in hydrochloric acid can reach to 99.113%. Infrared spectrometer was used for the imidazoline corrosion inhibitor intermediates and the quaternary ammonium and the structures were characterized. The complex with sodium sulfite, potassium iodide, sodium lauryl sulfate, potassium pyroantimonate, glycerol, OP-10, propargyl alcohol, isopropyl alcohol and thiourea were researched. The better mixtures with good synergy were selected and the best ratios were obtained.
TL;DR: In this paper, two semiconductors (Cu2O and TiO2) were chosen for the photocatalytic reduction of bicarbonate to formate in order to perform a systematic study on the effect of six different hole (h+) scavengers.
Abstract: Two semiconductors (Cu2O and TiO2) were chosen for the photocatalytic reduction of bicarbonate to formate in order to perform a systematic study on the effect of six different hole (h+) scavengers. The six h+ scavengers selected forthe study include glycerol, ethylene glycol, 2-propanol, sodium sulfite, triethanolamine, and ethylenediaminetetraacetic acid. Glycerol proved to be the most efficient h+ scavenger, and TiO2 in glycerol showed the highest quantum efficiency of 5.04 ± 0.3%. This finding bodes well as a sustainable one because glycerol is environmentally benign, a low-cost material, and is derived from plants, as opposed to petroleum sources like 2-propanol or ethylene glycol.
TL;DR: In this article, the possibility of reduction of chromium(VI) compounds by solutions of titanium(III) chloride in hydrochloric acid has been investigated and it has been shown that the considered reagent possesses strong reductive properties over wide pH range.
Abstract: The possibility of reduction of chromium(VI) compounds by solutions of titanium(III) chloride in hydrochloric acid has been investigated. It has been shown that the considered reagent possesses strong reductive properties over wide pH range. It has been proved that the efficiency of the reduction of chromium(VI) compounds with titanium(III) chloride in neutral medium is much higher than that when using sodium sulfite. It has been noted that in addition to the reduction properties, titanium compounds act as a highly efficient coagulant, thereby increasing the overall purification efficiency of the wastewater.
Patent•
17 Aug 2018
TL;DR: In this paper, a selection method of lead and zinc sulfide ore is presented, which is based on the steps of milling of raw ore, flotationof lead and flotation of zinc, wherein during rough flotation, lead, lime, calcium hypochlorite, zinc sulfate, sodium sulfite and sodium sulfide are added.
Abstract: The invention discloses a selection method of lead and zinc sulfide ore, and belongs to the technical field of beneficiation. The selection method comprises the steps of milling of raw ore, flotationof lead and flotation of zinc, wherein during rough flotation of lead, lime, calcium hypochlorite, zinc sulfate, sodium sulfite, sodium sulfide, dimethyl dicarbonate, ethyl thio carbamate, sodium n-butylxanthate, dianilinodithiophosphoric acid, diphenyl amino phosphorodithioic acid and sodium carbonate are added; during fine flotation of lead, lime, zinc sulfate, sodium sulfite and sodium sulfideare added; during scavenging of lead, lime, calcium hypochlorite, zinc sulfate, sodium sulfite, sodium sulfide, dimethyl dicarbonate, ethyl thio carbamate, dianilinodithiophosphoric acid, diphenyl amino phosphorodithioic acid and sodium carbonate are added; during rough flotation of zinc, lime, copper sulfate, ammonium sulfite, sodium n-butylxanthate and terpenic oil are added; during fine flotation of zinc, lime is added; and during scavenging of zinc, lime, copper sulfate, ammonium sulfite, sodium n-butylxanthate and terpenic oil are added. By adoption of the selection method of lead and zinc sulfide ore, the problem that when a traditional flotation method is used for selecting lead and zinc sulfide ore, the recovery rate of lead and zinc is low is solved.
Patent•
13 Apr 2018
TL;DR: In this paper, a high-performance polycarboxylate water reducer and a preparation method for its use was presented. But the method is not suitable for the case of water reduction.
Abstract: The invention discloses a high-performance polycarboxylate water reducer and a preparation method thereof. The high-performance polycarboxylate water reducer is prepared from the following raw materials: acrylic acid, mercaptoacetic acid, isoamylene alcohol polyoxyethylene ether, hydrogen peroxide, vitamin, white sugar, sodium dodecyl sulfate, solid naphthalene, concentrated sulfuric acid, formaldehyde, caustic soda liquid, polyethylene glycol monoethylether methacrylic ester, calcium lignosulphonate, an ethylene oxide-propylene oxide copolymer, trehalose, shale ash, sodium hydrogen sulfite, polyoxyethylene, aluminum triphosphate, oleic acid diethanolamide, dinonylnaphthalene sulfonic acid, urotropin, an additive, acetone, sodium sulfite, acrylamide, an initiating agent and water. The preparation method comprises the following steps: mixing the isoamylene alcohol polyoxyethylene ether and the like; after the solid naphthalene is processed, adding a silicone powder into the processed solid naphthalene and stirring the mixture; processing the acrylamide and the like; finally, mixing products obtained in the former three steps, so as to obtain the high-performance polycarboxylate water reducer. The high-performance polycarboxylate water reducer has the advantages that the corrosion resistance and the water reducing rate can be improved, and the slump loss is smaller.
Patent•
27 Apr 2018
TL;DR: In this paper, a technique for producing sodium sulfite products by absorption of SO2 flue gas through arsenic-containing industrial alkali residue water alkali liquor and arsenic removal purification is presented.
Abstract: The invention provides a technique for producing sodium sulfite products by absorption of SO2 flue gas through arsenic-containing industrial alkali residue water alkali liquor and arsenic removal purification. The technique comprises the following steps: pulverizing arsenic-containing industrial alkali residues, adding water, pulping and then carrying pressure filtration; adding a sodium sulphideaqueous solution in obtained leachate, carrying out filter pressing after treatment through p-phenylenediamine to obtain arsenic-containing leached clear alkali liquor; pumping the clear liquor into aspraying and desulfurizing tower to absorb SO2 flue gas so that the pH value of absorbing liquor to be reduced to 6.2-6.4; adding the arsenic-containing leached clear alkali liquor and adjusting thepH value to be 10.5-11.5, then adding a polymeric ferric sulfate aqueous solution and carrying out arsenic precipitating; carrying out filter pressing to separate liquid from solid; carrying out concentration and evaporation of the clear liquor and then crystallizing; and separating motor liquid and then drying to obtain the sodium sulfite products of which the mass concentration is greater than or equal to 96%. On the premise of ensuring industrial stable production and increasing the content of the sodium sulfite products, the technical process and parameter selection are optimized, obvioustechnological progress is obtained, if 20,000 tons of alkali residues are produced every year in the whole country, about 35,000,000 yuan of economic benefit can be increased, the total amount of arsenic As treated harmlessly by arsenic removal can be 6%* 20,000= 1,200 tons per year, 4,250 tons of sulfur is removed every year, and huge environmental protection benefit can be produced.
Patent•
02 Feb 2018
TL;DR: In this article, a catalytic cracking-flue gas dust removal, desulfurization and sodium sulfite recovery process is described, which adopts a bag type dust collector and a booster fan.
Abstract: The invention discloses a catalytic crackingflue gas dust removal, desulfurization and sodium sulfite recovery process which adopts a dust removal system, a desulfurization system and a sodium sulfiterecovery system. The dust removal system is a bag type dust collector 1. The desulfurization system is a desulfurization tower 3, the desulfurization tower 3 comprises a spraying layer 4, a demister5 and a chimney 6 are arranged above the spraying layer 4. The bag type dust collector 1 is connected with the desulfurization tower 3 through a booster fan 2. The sodium sulfite recovery system comprises a crystallizer 7, a thickening device 8 and a centrifugal machine 10, wherein the thickening device 8 is arranged before the centrifugal machine 10, the crystallizer 7, the thickening device 8 and the centrifugal machine 10 are sequentially connected through pipes, and a fluidized-bed dryer 11 and a cyclone separator 12 are sequentially connected behind the centrifugal machine 10. The thickening device 8 is also connected with an overflow buffer tank 9, and the overflow buffer tank 9 is also connected with the desulfurization tower 3. The process is high in sodium sulfite recovery rate while meeting current environmental protection standard, obtained products are high in purity, almost no wastewater is discharged, and the catalytic crackingflue gas dust removal, desulfurization and sodium sulfite recovery process has the advantages of being low in operation cost, obvious in economic and environmental benefit and the like.
TL;DR: In this article, the authors investigated the solubilities of NaPTS, Na2SO3, NaCRS, and NaMethylphenoxide (NaCRS) in aqueous NaOH solutions and Na 2SO3 in aaqueous ethanol solutions.
Abstract: The solubilities of sodium p-toluenesulfonate (NaPTS), sodium sulfite (Na2SO3), and sodium p-methylphenoxide (NaCRS) in aqueous NaOH solutions and Na2SO3 in aqueous ethanol solutions were investigated using a dynamic method over the temperature range from 277 to 341 K at atmospheric pressure. The experimental results showed that the solubilities of NaPTS, Na2SO3, and NaCRS in aqueous NaOH solutions and Na2SO3 in aqueous ethanol solutions decreased distinctly with the solute-free mass fraction of NaOH (w40) and ethanol (w50). Further, there were obvious transition points in the solubility–temperature curves of NaPTS and Na2SO3 in aqueous NaOH solutions, and the transition points shifted to lower temperature as w40 rose. The forming of transition point was due to the different equilibrium solid phase, which was revealed by characterization of the equilibrium solid phase. But the transition points in the solubility–temperature curves of Na2SO3 in aqueous ethanol solutions remained constant at different w50 v...
TL;DR: This study mainly aims to explore the influences of several fundamental aspects on the photoinduced synergy as well as discuss the detailed mechanisms, to provide some insight into detoxifying water contaminants in practical applications and developing other novel photoinduced synergistic systems with high performance.
Patent•
10 Aug 2018
TL;DR: In this article, a cyanide-free plated gold formula and a production technology were presented, in particular to a gold plating technology and a gold formula consisting of gold chlorate, anhydrous sodium sulfite, dipotassium phosphate, potassium citrate, potassium chloride, ethylene diamine tetraacetic acid, brightening agent and stabilizing agent.
Abstract: The invention relates to the technical field of gold plating technology, in particular to a cyanide-free plated gold formula and a production technology. The formula comprises gold chlorate, anhydroussodium sulfite, dipotassium phosphate, potassium citrate, potassium chloride, ethylene diamine tetraacetic acid, brightening agent and stabilizing agent. In plating liquid, the concentration of goldchlorate is 8-15 g/L, the concentration of anhydrous sodium sulfite is 120-150 g/L, the concentration of dipotassium phosphate is 30-50 g/L, the concentration of potassium citrate is 80-100 g/L, the concentration of potassium chloride is 100-120 g/L, the concentration of ethylene diamine tetraacetic acid is 20-30 g/L, and the concentration of brightening agent is 0.5-1.5 g/L. According to the scheme, the cyanide-free plated gold formula and the production technology have the advantages that the gold deposition speed is high, plating liquid stability is high, the plating liquid dispersion ability is high, the plating layer quality is improved, and plating layer uniformity is improved.
Patent•
18 May 2018
TL;DR: In this article, an aliphatic water reducer is described, which is made from 5-10 parts of cyclohexanone, 6-12 parts of sodium sulfite, 10-20 parts of acrolein, 0.5-2 parts of styrene sulfonic acid, 4-9 parts of ammonium sulfate and 2-6 parts of concentrated sulfuric acid.
Abstract: The invention relates to the field of water reducers, in particular to an aliphatic water reducer and a preparation method thereof. The water reducer is prepared from, by weight, 5-10 parts of cyclohexanone, 6-12 parts of sodium sulfite, 10-20 parts of acrolein, 0.5-2 parts of styrene sulfonic acid, 4-9 parts of sodium nitrite, 2-6 parts of concentrated sulfuric acid, 3-8 parts of calcium hydroxide, 3-7 parts of citric acid, 4-11 parts of hydrogen peroxide, 2-6 parts of ferric sulfate and an appropriate amount of water. To some extent, the water reducer effectively overcomes the defects that an existing water reducer is prone to mildewing and low in production efficiency.
TL;DR: In this paper, a family of neodymium(III) compounds containing either sulfite or a mixture of hydrogen-sulfate and sulfite ligands has been hydrothermally synthesized.
Abstract: A family of four new neodymium(III) compounds containing either sulfite or a mixture of hydrogen-sulfate and sulfite ligands has been hydrothermally synthesized. The low solubility of lanthanide sulfite compounds has, in the past, made the isolation of single-crystalline products difficult. To obtain these phases, sodium sulfite (Na2SO3) and sodium bisulfite (NaHSO3) were employed as both anion sources and pH regulators. The in situ oxidation of sulfite to sulfate was controlled by dictating the pH of the starting solutions with these ligands. Sulfites were found to form at a neutral pH, whereas, when the pH was increased, the oxidation of sulfite to sulfate was observed in the crystalline products. The products discussed herein reveal the pH controlled process of in situ oxidation in these hydrothermal reactions.
Patent•
24 Aug 2018
TL;DR: In this article, a monovalent gold cyanide-free gold electroplating bath based on alkaloid compound coordination and application thereof is described, in which a mixture of dipotassium phosphate, sodium tetraborate, citric acid and potassiumcitrate is used as the pH buffering agent.
Abstract: The invention discloses a monovalent gold cyanide-free gold electroplating bath based on alkaloid compound coordination and application thereof. The electroplating bath comprises monovalent gold salt,a coordination agent I, a coordination agent II, a pH buffering agent (used as conducting salt at the same time), a wetting agent and an additive, wherein sodium sulfite containing monovalent gold isused as main salt; sodium sulfite is used as the coordination agent I; alkaloid is used as the coordination agent II; a mixture of dipotassium phosphate, sodium tetraborate, citric acid and potassiumcitrate is used as the pH buffering agent (used as conducting salt at the same time); polyoxy organic matter is used as the wetting agent; and a heterocyclic organic compound is used as the additive.The cyanide-free gold electroplating bath is stable and is still clear and colorless after being placed for a long time, the replacement resistance is high, and the phenomenon of a replaced gold layer is avoided after a fresh nickel plate is arranged in the electroplating bath for 5 min; and the even-plating capacity is good, and under the rated electroplating conditions, an obtained gold coatingis good in bonding force with a substrate and bright and yellow in appearance.
Patent•
13 Nov 2018
TL;DR: In this paper, a method for recovering lead from a lead-acid storage battery dismantling paste by a full-wet method was proposed, which is more convenient, no SOxand dust are generated, the pollution environment is avoided, and the environment is protected.
Abstract: The invention discloses a method for recovering lead from a lead-acid storage battery dismantling paste by a full-wet method The method comprises the following steps that S1, after the lead-acid storage battery is disassembled, and the collected lead paste is converted into carbonate (desulfurization reaction) by adopting sodium carbonate or ammonium carbonate, wherein the main chemical reactionis PbSO4 and (NH4)2CO3 generate prexipated PbCO3 and (NH4)2SO4; PbSO4 and Na2CO3 generate prexipated PbCO3 and Na2SO4; S2, the PbO2 in the lead paste is converted into PbO (reduction reaction) by adopting sodium sulfite or ammonium sulfite, and the main chemical reaction is as follows According to the method, the high-temperature condition of a pyrogenic process is avoided, the operation is moreconvenient, and meanwhile, the reaction is more energy-saving, the reaction is in a normal-temperature normal-pressure reaction in the whole process, and the implementation is more convenient, no SOxand dust are generated, the pollution environment is avoided, and the environment is protected; compared with pyrogenic process, the process flow is short, the investment is saved, the process adjustment is flexible, and the metal recovery rate is high
Patent•
04 Dec 2018
TL;DR: In this paper, a platinum refining method is described, which includes the following steps: adding water to ammonium chloroplatinate, slurrying the crude ammonium and water to obtain a slurry, heating the slurry to 90-95 DEG C, and adding sodium sulfite or sodium pyrosulfite while stirring until the ammonium chloride is completely dissolved.
Abstract: The invention discloses a platinum refining method. The method comprises the following steps: adding water to crude ammonium chloroplatinate, slurrying the crude ammonium chloroplatinate and water toobtain a slurry, heating the slurry to 90-95 DEG C, and adding sodium sulfite or sodium pyrosulfite while stirring until the crude ammonium chloroplatinate is completely dissolved; cooling the obtained solution, filtering the cooled solution, heating the obtained filtrate to 90-95 DEG C, adding hydrochloric acid and sodium chlorate with stirring, and stopping the addition of the hydrochloric acidand sodium chlorate when no ammonium chloroplatinate crystals are precipitated from the solution; cooling the obtained solution to room temperature, adding ammonium chloride, performing stirring to dissolve the ammonium chloride, and filtering the obtained solution to obtain a solid that is pure ammonium chloroplatinate; washing the obtained pure ammonium chloroplatinate with a hydrochloric acid and ammonium chloride mixed solution; and repeating above steps to obtain pure ammonium chloroplatinate, and finally carrying out high-temperature calcination on the pure ammonium chloroplatinate to obtain spongy platinum. The method avoids ammonium chloroplatinate calcination, aqua regia dissolution and the like, overcomes excessive palladium in the spongy platinum and other problems caused by insufficient nitrate removal of the platinum in the sponge platinum, and obtains the spongy platinum with a purity reaching up to 99.99%.
TL;DR: In this article, the process of leaching oxidized nickel ore in sulphuric acid with the additives of sodium sulfite and fluoride is investigated, and it is shown that at NaF consumption of 10 kg/t, it is possible to enhance the maximum extraction of nickel to solution from 82.3-86.9 to 96.0-98.7% at the residual sulfite concentration of 10−20 g/l in the working bath.
Abstract: The process of leaching oxidized nickel ore in sulphuric acid with the additives of sodium sulfite and fluoride is investigated. Tochilnogorsky deposit ore (Sverdlovsk Region) is used to prove theoretically and experimentally efficient application of fluoride in dissociation of nickel minerals (nontronite and garnierite) in oxidized nickel ore. It is shown that at NaF consumption of 10 kg/t, it is possible to enhance maximum extraction of nickel to solution from 82.3–86.9 to 96.0–98.7% at the residual sulphuric acid concentration of 10–20 g/l in the working bath. It is found that the sodium fluoride additives lower the process activation energy from 22.8 to 12.9 kJ/mole. This means that the reaction of sulphuric-acid leaching proceeds in diffusion–kinetic mode and that sodium fluoride is applicable as the leaching accelerator.
Patent•
10 Apr 2018
TL;DR: In this article, a novel gear oil formula consisting of 5-15% of hydrogenated base oil, 1-5% of sodium sulfite and 1-10% of ammonium dodecyl benzene carbonate was presented, which has relatively strong extreme pressure antiwear property and relatively strong oxidation resistance.
Abstract: The invention discloses a novel gear oil formula. The raw materials in the formula comprise the following components in percentage by weight: 5-15% of hydrogenated base oil, 1-5% of sodium sulfite, 1-10% of sodium dodecyl benzene carbonate, 5-15% of butylated hydroxytoluene, 3-9% of potassium metaborate, 2-3% of polydimethylsiloxane, 1-5% of oleamide, 5-7% of an antioxidant preservative, 3-5% of ametal deactivator, 3-5% of an anti-rust agent, 1-5% of an anti-foaming agent, 5-10% of an oiliness agent and 4-5% of a demulsifying agent. The novel gear oil has relatively strong extreme pressure antiwear property and relatively strong oxidation resistance.
Patent•
17 Aug 2018
TL;DR: In this paper, a beneficiation method for copper-lead sulphide ore, which belongs to the technical field of beneficiation, has been proposed, which consists of raw ore grinding and mixing flotation.
Abstract: The invention discloses a beneficiation method for copper-lead sulphide ore, and belongs to the technical field of beneficiation. The method comprises raw ore grinding, copper-lead mixing flotation and copper-lead separation. Copper-lead mixing flotation comprises primary copper-lead roughing, tertiary copper-lead fine selecting and secondary copper-lead scavenging. Copper-lead separation comprises primary copper roughing, tertiary copper fine selecting and secondary copper scavenging. Lime, calcium hypochlorite, zinc sulfate, sodium sulfite, sodium sulphide, dimethyl dicarbonate, sodium pyrophosphate, sodium citrate, ethionine ester, ethyl thio carbamate, sodium n-butylxanthate, aniline aerofloat, diphenyl amino phosphorodithioic acid and sodium carbonate are added in the copper-lead roughing and copper-lead scavenging processes. Lime, water glass, sodium phosphate starch, carboxymethyl starch, phthalic acid, thiosalicylic acid, ethionine ester and sodium ethylxanthate are added in the copper roughing and copper scavenging processes. The beneficiation method solves the problem that in the process of beneficiation of the copper-lead sulphide ore through a traditional flotation method, the copper and lead recycling rate is low.
Patent•
13 Apr 2018
TL;DR: In this article, a method for recycling a lithium battery copper current collector by using sodium sulfite is proposed. But the method is not applicable for large-scale production of factories.
Abstract: The invention provides a method for recycling a lithium battery copper current collector by using sodium sulfite. The method comprises the following steps: firstly adopting diluted hydrochloric acid to dissolve a positive electrode material; completely converting metallic elements in the positive electrode material into an ion form, and then adding sodium sulfite so that bivalent copper is reducedinto monovalent copper and forms a cuprous chloride-sodium chloride complex with sodium ions; adding deionized water for attenuation through a filter liquor so as to obtain a cuprous chloride sediment; after filtering again, adding cobalt, nickel, manganese and lithium in the filter liquor according to a raw material ratio for carrying out hydro-thermal synthesis, and thus obtaining the novel lithium ion positive electrode material. According to the method, the problem that a copper current collector is low in separation efficiency and is unlikely to separate from nickel, cobalt and manganesein the traditional technology is solved, and the recycling efficiency of copper element is improved; and moreover, the method is simple in working procedures and low in cost, and is applicable for large-scale production of factories.
Patent•
29 Jun 2018
TL;DR: In this paper, a method for comprehensive recovery of lead, mercury and selenium in copper smelting acid mud is presented. But the method is not suitable for the use of lead-containing filter residue returning process.
Abstract: The invention relates to a method for comprehensive recovery of lead, mercury and selenium in copper smelting acid mud, and belongs to the technical field of comprehensive utilization of solid waste.The method for comprehensive recovery of lead, mercury and selenium in copper smelting acid mud specifically includes the following steps that copper smelting acid mud and a nitric acid solution are mixed at a liquid-solid ratio of 5:1, the stirring rate is 500 r/min, and sodium hypochlorite is gradually added and reacted at normal temperature for 60 minutes to obtain a mixed solution containing mercury chloride and selenic acid; separated filter residues are sent to a lead smelting system for recycling, and sodium hypophosphite is added into filtrate to reduce ionized mercury in the solutionto settleable elemental mercury, after flocculation and sedimentation, the mercury-containing slag is separated by microfiltration, and refined mercury is obtained by continuous rectification and purification; and sodium sulfite is added into the filtrate for reduction to obtain crude selenium, and the wastewater can be returned to the leaching process for recycling after neutralization reaction.The method for comprehensive recovery of lead, mercury and selenium in copper smelting acid mud adopts leaching and sectional reduction to realize effective separation of mercury and selenium, the recovery rate of selenium is 98.7%, and the recovery rate of mercury is up to 98.9%. The operation is simple, the cost is low, and the lead-containing filter residue returning process after leaching canrealize comprehensive utilization of resources.