scholarly journals Preparation of Calcium Stannate from Lead Refining Dross by Roast–Leach–Precipitation Process

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 283 ◽  
Author(s):  
Dixiu Wu ◽  
Junwei Han ◽  
Wei Liu ◽  
Fen Jiao ◽  
Wenqing Qin
Keyword(s):  
Precipitation Process ◽  
Lead Smelter ◽  
Solid Ratio ◽  
Lead Refining ◽  
Average Grain Size ◽  
Naoh Solution ◽  
Leaching Solution ◽  
Leaching Parameters ◽  
Optimized Conditions ◽  
Calcium Stannate

Lead refining dross containing plenty of tin and other heavy metals, such as lead and antimony, is considered a hazardous waste generated in large quantities in lead smelter plants. In this study, calcium stannate was synthesized from lead refining dross using sodium carbonate roasting and alkaline leaching followed by precipitation with CaO. The effect of roasting and leaching parameters on the extraction efficiency of tin was investigated. The leaching efficiency of tin reached 94% under the optimized conditions: roasting with 60% Na2CO3 at 1000 °C for 45 min, and leaching using 2 mol/L NaOH solution for 90 min at 85 °C and 8 cm3/g liquid/solid ratio. Furthermore, more than 99% of tin in the leaching solution was precipitated using CaO. Finally, XRD, SEM, and ICP-OES analyses indicated that the final CaSnO3 product had a purity of 95.75% and its average grain size was smaller than 5 μm. The results indicated that the developed method is feasible to produce calcium stannate from lead refining dross.

A novel separation method of the valuable components for activated clay production wastewater

2021 ◽  
Vol 19 (1) ◽  
pp. 530-540
Author(s):  
Lvshan Zhou ◽  
Tongjiang Peng ◽  
Hongjuan Sun ◽  
Dong Fu ◽  
Chuan Lai
Keyword(s):  
Aluminum Phosphate ◽  
Iron Phosphate ◽  
Acid Sites ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Iron Aluminum ◽  
Phosphorus Iron ◽  
Optimized Conditions ◽  
Acidic Wastewater

Abstract The acidic wastewater produced by the wet production of activated clay contains valuable components such as iron and aluminum. The precipitation method was successfully introduced to separate iron and aluminum from the activated clay production wastewater step by step, which can not only recover the valuable components, but also avoid environmental pollution. In the separation process, gypsum, iron aluminum phosphate, alumina, and sodium sulfate were prepared, and the phase compositions of separation products were analyzed by XRD and IR. The main influencing factors in the separation of iron and aluminum components were studied by single factor experiment. The results show that at the optimized conditions, phosphorus/iron molar ratio 6.0, the system pH 3.0, the reaction temperature 343 K, and the reaction time 90 min, the iron(iii) ion in the system can form a sodium-containing aluminum iron phosphate double salt, and the filtrate after separating Fe3+ and part of Al3+ can meet the requirements for forming high-purity Al2O3. During the phosphate precipitation process, the hypothesis should be correct that Al3+ reacts with PO 4 3 − {\text{PO}}_{4}^{3-} to form an AlPO4 skeleton, Fe3+ isomorphically replaces Al3+ in the [AlO4] tetrahedron, and adsorption occurs simultaneously, with Na+ occupying the terminal acid sites, P(Al)–OH.

Separation of sodium chromate from high alkaline media based on precipitation transformation using barium hydroxide

2020 ◽  
Vol 44 (28) ◽  
pp. 12048-12057
Author(s):  
Xiaoyu Tang ◽  
Haifeng Wu ◽  
Xuejun Quan ◽  
Chengfei Feng ◽  
Gang Li ◽  
...  
Keyword(s):  
Barium Hydroxide ◽  
Alkaline Media ◽  
Precipitation Process ◽  
Sodium Chromate ◽  
High Concentration ◽  
Naoh Solution

Separation and recovery of chromium from a high-concentration NaOH solution by a Ba(OH)2 precipitation process.

Empirical Model to Estimate Mn2+ Precipitation Rate from a Leaching Solution Using SO2/O2 as Oxidizing Agent

2012 ◽  
Vol 1380 ◽  
Author(s):  
S. Bello-Teodoro ◽  
R. Pérez-Garibay
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Reaction Rates ◽  
Precipitation Process ◽  
Low Grade ◽  
Gas Flow Rate ◽  
Oxidative Precipitation ◽  
Leaching Solution ◽  
Good Concordance ◽  
Main Influence

ABSTRACTA method, based in leaching with SO2, to process low grade pyrolusite minerals has shown good results at laboratory scale. After the separation of the solid impurities, the dissolved manganese is subsequently precipitated using the SO2/O2 gas mixture as oxidising agent. In this research it was obtained a mathematical model to estimate the oxidative precipitation process, as a function of temperature, pH and SO2 gas flow rate. It was found that pH and temperature have the main influence in the reaction rate. An optimal SO2 concentration in the mixture must be used to avoid generation of reductive conditions. It was observed a most efficient reaction with a low gas flow rate injection. The predicted reaction rates presents a good concordance with the experimental results (R2=0.97), showing a worthy potential for practical uses.

scholarly journals Efficient Separation of Silicon and Vanadium by Sodium Roasting-Water Leaching from Vanadium Slag and CaV2O6 Preparation

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 255
Author(s):  
Changqing Li ◽  
Haichao Zhang ◽  
Ma Tao ◽  
Xufeng Wang ◽  
Hang Li ◽  
...  
Keyword(s):  
New Product ◽  
Molar Ratio ◽  
Migration Behavior ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Solid Ratio ◽  
Leaching Solution ◽  
Micro Morphology ◽  
Precipitation Ratio ◽  
Separation Behavior

Calcium vanadate (CaV2O6), a new product of vanadium precipitation, was obtained from vanadium slag by sodium roasting-water leaching and calcium precipitation. The separation behavior of vanadium and silicon in vanadium slag during sodium roasting and water leaching was systematically studied, and micro-morphology and valence migration behavior of vanadium and Fe in vanadium slag, roasting slag, and residue were revealed. The Na2CO3 was added to the vanadium slag at 20% mass fraction, roasted at 790 ℃, and kept for 120 min, the roasted sample was added to the deionized aqueous solution with a liquid-solid ratio of (L/S) 5mL/g, and then heated at 90 ℃ for 60 min, 89.54% vanadium and 1.96% chromium were extracted. Sodium carbonate tends to combine with vanadium to form sodium vanadate, while silicon is easy to combine with Fe and Na to form acmite (NaFeSi2O6). When the molar ratio of N (Ca/V) is 0.6 and CaO, is added to adjust the pH of vanadium leaching solution to 6.7 ± 0.1 and precipitate 90 min at 90 ℃, vanadium is precipitated in the form of CaV2O6 with a purity of 95.69%, under these conditions, the precipitation ratio is 95.03%.

Zinc carbonate recovery from brass melting slag

2021 ◽  
Vol 98 ◽  
pp. 14-18
Author(s):  
Thao Nguyen Thi ◽  
◽  
Nam Pham Ky ◽  
Ngoc Tran Vu Diem
Keyword(s):  
Sulfuric Acid ◽  
High Purity ◽  
Room Temperature ◽  
Ph Value ◽  
Zinc Carbonate ◽  
Leaching Solution ◽  
Optimized Conditions ◽  
Melting Slag

Brass melting slag (20.38 wt.% Zn) was leached in sulfuric acid with concentration of (50 + 80) g/l H2SO4, leaching temperature of (30 + 60) °C for (30 + 120) min. The optimized conditions for 94.16% Zn extraction from brass melting slag were found as 70 g/l H2SO4, room temperature and 90 min. The leaching solution was purified by removal of Fe through Fe(OH)3 precipitation when adding ZnO to adjust pH value of 5. The solution was continuously cemented by Zn metal at 60 °C for 60 min to obtain Cu metal with high purity of 99 wt.% Cu. The purified solution with 37.64 g/l Zn was modified by Na2C03 to have pH value of about 6 and precipitation of ZnC03 (94.14 %).

Recovery of molybdenum from alkali leaching solution of low-grade molybdenum concentrate by ion exchange

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Zhaoguo Gao ◽  
Bo Zhang ◽  
Hongzhao Liu ◽  
Wei Wang ◽  
Yaohua Cao
Keyword(s):  
Ion Exchange ◽  
Adsorption Capacity ◽  
Ammonia Solution ◽  
National Standard ◽  
Precipitation Process ◽  
Low Grade ◽  
Loaded Resin ◽  
Dynamic Experiments ◽  
Alkali Leaching ◽  
Leaching Solution

AbstractIn order to extract molybdenum (Mo) from alkali leaching solution of low-grade Mo concentrate, static and dynamic ion exchange experiments were performed. The static experiments results indicated that the adsorption capacity of D201 resins reached 93.50% at pH 3.5, while the adsorption capacity of D314 resins was 95.47%. Therefore, D314 resin was adopted for further experiments. The dynamic experiments results indicated that the adsorption capacity of Mo reached 96.77% when the flow rate of leaching solution was 1 ml/min. The loaded resin could be desorbed by 10% ammonia solution. In consequence, the maximum concentration of Mo in eluate was 122 g/l. In the precipitation process, the Mo recovery reached 97.81%, and the obtained Mo oxide products met the requirement of YMo 55 national standard in GB/T24482-2009 and Grade A standard of ASTM A146-04 (2014).

scholarly journals Selective Separation of Arsenic from Lead Smelter Flue Dust by Alkaline Pressure Oxidative Leaching

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 308 ◽  
Author(s):  
Wei Liu ◽  
Zihan Li ◽  
Junwei Han ◽  
Wenhua Li ◽  
Xun Wang ◽  
...  
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Leach Solution ◽  
Selective Separation ◽  
Lead Smelter ◽  
Solid Ratio ◽  
Flue Dust ◽  
Calcium Arsenate ◽  
Oxidative Leaching ◽  
Leaching Efficiency

This study investigated the feasibility of using an alkaline pressure oxidative leaching process to treat lead smelter flue dust containing extremely high levels of arsenic with the aim of achieving the selective separation of arsenic. The effects of different parameters including NaOH concentration, oxygen partial pressure, liquid-to-solid ratio, temperature, and time for the extraction of arsenic were investigated based on thermodynamic calculation. The results indicated that the leaching efficiency of arsenic reached 95.6% under the optimized leaching conditions: 80 g/L of NaOH concentration, 1.0 MPa of oxygen partial pressure, 8 mL/g of liquid-to-solid ratio, 120 °C of temperature, 2.0 h of time. Meanwhile, the leaching efficiencies of antimony, cadmium, indium and lead were less than 4.0%, basically achieving the selective separation of arsenic from lead smelter flue dust. More than 99.0% of arsenic was converted into calcium arsenate product and thus separated from the leach solution by a causticization process with CaO after other metal impurities were removed from the solution with the addition of Na2S. The optimized causticization conditions were established as: 4.0 of the mole ratio of calcium to arsenic, temperature of 80 °C, reaction time of 2.0 h. The resulting product of calcium arsenate may be used for producing metallic arsenic.

Recovery of Copper and Cobalt from Spent Aerospace Material with Pollution-Free Oxidant

2012 ◽  
Vol 476-478 ◽  
pp. 357-360 ◽  
Author(s):  
Yue Bin Xiao ◽  
Xue Jiao Zhou ◽  
Lei Cao ◽  
Ya Gao ◽  
Da Liu ◽  
...  
Keyword(s):  
Acid Leaching ◽  
Agitation Speed ◽  
Temperature Reaction ◽  
Initial Concentration ◽  
Solid Ratio ◽  
Aerospace Material ◽  
Valuable Element ◽  
C 30 ◽  
Optimized Conditions ◽  
Free Oxidation

The acid leaching of spent aerospace material with pollution-free oxidation is discussed. Effect of parameters including initial concentration of hydrochloric acid solution, leaching temperature, reaction time, agitation speed, liquid to solid ratio and concentration of oxidant on valuable element extractions are determined, the optimized conditions are 6 M, 60 °C, 30 min, 250 r/min, 6:1 and 0.0378 mol•L-1•min-1, respectively. The comprehensive results of experiments show that the extracting efficiency of Co and Cu are over 83% and 98% respectively when optimized conditions were adopted.

scholarly journals The Effects of Extraction Conditions on Extraction Yield and Syringin Content in Producing Standardized Tinospora crispa Aqueous Extract with High Antioxidant Activity

2021 ◽  
pp. 106-120
Author(s):  
Zamree Md Shah ◽  
Mohd Kamal Nik Hasan ◽  
Khairul Kamilah Abdul Kadir ◽  
Mohd Shahidan Mohd Arshad ◽  
Zulkhairi Amom
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Pharmaceutical Preparations ◽  
Extraction Yield ◽  
Extraction Time ◽  
Extraction Temperature ◽  
Solid Ratio ◽  
Beneficial Effects ◽  
High Antioxidant Activity ◽  
Optimized Conditions

The herbal plant known as Tinospora crispa is reported to have many beneficial effects on health and has great potential in future to be developed as a health product either in the form of traditional medicine, food supplements or in pharmaceutical preparations. However, so far knowledge on processing procedures to produce quality standardized extracts of this plant to be used in product development has still not widely reported. Therefore, the objective of this study was to determine the optimal extraction conditions for producing a standardized T. crispa aqueos extract (STCAE) with high extraction yield and high syringin content. Experiments were conducted to determine the effects of various extraction conditions involving temperature (25–100 ° C), extraction time (0.5–6 hours) and liquid (water) to solid ratio (5: 1–25: 1 ml of solvent per g stem dry). Using optimized conditions obtained, the extract was standardized based on syringin and was further investigated on its antioxidant activity through DPPH, FRAP and TBA bioassays. Results revealed that the optimum extraction conditions were found to be 1 h extraction time and 15:1 ml g−1 liquid-to-solid ratio. For the extraction temperature, 60°C was found to be the best. STCAE was produced on the basis of the extract to contain with at least 0.4 wt% of syringin. STCAE was found to possess high antioxidant activities through DPPH, FRAP and TBA bioassays.

scholarly journals Study on Extraction Separation of Thioarsenite Acid in Alkaline Solution by CO32--Type Tri-n-Octylmethyl-Ammonium Chloride

2021 ◽  
Vol 8 ◽  
Author(s):  
Kang Yan ◽  
Liping Liu ◽  
Hongxing Zhao ◽  
Lei Tian ◽  
Zhifeng Xu ◽  
...  
Keyword(s):  
Ammonium Chloride ◽  
Organic Phase ◽  
Extraction Rate ◽  
Alkaline Leaching ◽  
Extraction And Separation ◽  
Extraction Separation ◽  
Naoh Solution ◽  
Leaching Solution ◽  
Saturated Nahco ◽  
Formula Type

To overcome the problem of arsenic separation and enrichment from an alkaline leaching solution in arsenic-containing dust, a CO32--type tri-n-octylmethyl-ammonium chloride (TOMAC) method for extracting thioarsenite is proposed in this paper. Considering an alkaline leaching solution as the research object, after vulcanization pretreatment, TOMAC transformation and organic phase saturated extraction capacity were measured, and the extraction mechanism was preliminarily studied. First, Cl−-type quaternary ammonium salt was effectively transformed to HCO3--type by treating organic phase with saturated NaHCO3five times. TOMAC was effectively transformed from HCO3- to CO32- type by alkaline washing with 1.0 mol/l NaOH solution; this washing was repeated thrice. Thereafter, the effects of organic phase composition, phase ratio, extraction time, and temperature on the extraction and separation of arsenic were investigated. The results show that under the conditions of 30% CO32--type TOMAC + 15% sec-octanol + 55% sulfonated kerosene, VO/VA = 1/1, and 5 min extraction at room temperature, the single-stage extraction rate of AsIII is 85.2%. The AsIII concentration in raffinate can be reduced to less than 1.33 × 10−3 mol/l by four-stage countercurrent extraction, and the extraction rate of AsIII can exceed 98.4%.

Sign in / Sign up

Export Citation Format

Share Document