scholarly journals Leaching of lead from sphalerite concentrate direct leaching residue by hydrochloric acid and sodium chloride for preparation of lead oxides

2020 ◽  
Vol 56 (2) ◽  
pp. 247-255
Author(s):  
Y.-Y. Fan ◽  
Y. Liu ◽  
L.-P. Niu ◽  
T. Jing ◽  
T.-A. Zhang

The purpose of this study was to select and propose an applicable method for extracting lead from sphalerite concentrate direct leaching residue. A large number of experiments were conducted to extract lead from sphalerite concentrate direct leaching residue by hydrochloric acid and sodium chloride solution as leachates. The main optimum parameters were determined, such as a liquid-solid ratio of 17.5-1, a reaction temperature of 85?C, an initial hydrochloric acid concentration of 1.3 mol/L, an initial sodium chloride concentration of 300 g/L, and a reaction time of 60 min. Ninety-five percent of the zinc, 96.0% of the iron, and 93.7% of the lead were extracted into leachate at the optimum conditions. The lead in the leachate was in the form of [PbCl4]2-. After the leachate was purified to remove impurities, it was converted into lead oxalate by sodium oxalate as a precipitant. Finally, lead oxalate was decomposed to obtain lead oxide powders via a high-temperature calcination process.

2013 ◽  
Vol 734-737 ◽  
pp. 1033-1036
Author(s):  
Gui Fang Zhang ◽  
Peng Yan ◽  
Qing Rong Yang

Based on the benefication of the complex silicate ore containing scandium, the research about aid-leaching agent used in the leaching of the scandium concentrate was been conducted. And the suitable leaching agent and aid-leaching agent which the useful ions entered into leaching liquid and the harmful ions were kept in leaching residue were been found according to the experiment results. For the scandium of sample existed various complex silicate ore as isomorphism form, the research has adopted hydrochloric acid with aid-leaching agent to dissociate the silicate ore and make scandium entering into solution. The research results has shown that the scandium leaching rate could reach 92.06% under the optimal conditions which the hydrochloric acid concentration is 22.8%, the dosage of aid leaching agent is 6%, liquid solid ratio is 4:1, particle size of leaching material totally is less than 0.15mm and leaching time is 8h.


2013 ◽  
Vol 469 ◽  
pp. 117-120 ◽  
Author(s):  
Fan Zhang ◽  
Xiao Jun Ma

In order to improve the adsorption performance of wooden activated carbon fibers (WACFs) and enlarge its application in food safety and fresh, the charcoal dust is used as pore-forming agent, and the absorption performance of WACFs for methylene blue (MB) by changing the liquid-solid rate, charcoal content, synthetics content and hydrochloric acid concentration is studied. The results show that: with the increase of liquid-solid ratio, the absorption capacity of WACFs for MB increases accordingly; with the increase of charcoal content and synthetics content, the absorption capacity both show the tendency of increasing first then reducing after accordingly, with the maximum absorption capacities of 534.61mg·g-1and 527.25mg·g-1respectively reached by 1% charcoal content and 4% synthetic content. When the hydrochloric acid concentration was below 15%, the absorption capacity increases linearly, while reduced when hydrochloric acid concentration was over 15%.


2012 ◽  
Vol 524-527 ◽  
pp. 1947-1950 ◽  
Author(s):  
Lei Zhang ◽  
Hao Wang ◽  
Yu Li

The experiments selected Wang Taipu gangue as raw materials and adopted single factor experimental method to study the leaching of aluminum oxide from gangue by using hydrochloric acid as leaching medium. The experiments studied solvent/sample mass ratio, hydrochloric acid/sample, liquid-solid ratio, hydrochloric acid concentration, leaching time and leaching temperature on Al2O3 leaching rate of coal gangue. Through the parallel experiment of the above factors, we can found that optimization conditions of hydrochloric acid leaching of alumina were: solvent /sample mass ratio: 0.20, solvent: NaF, liquid-solid ratio: 1:10, hydrochloric acid concentration: 6mol/L, leaching time: 150min, leaching temperature:110°C. In this case, the aluminum oxide of optimal leaching rate was 79.33%.


2019 ◽  
Vol 268 ◽  
pp. 06010
Author(s):  
John Rhen Uy ◽  
Neil Dominic Careo ◽  
Dominick Llarena ◽  
John Raymond Barajas

Cacao farming in the Philippines is continually expanding due to an influx of government support and funding. Although a comprehensive development program was implemented, the large volume of cacao biomass waste generated annually remains underutilized. In an attempt to provide a means of reusing this waste, we test the extent to which furfural can be extracted from cacao pod wastes. A box-behnken experimental design was used to obtain the optimal conditions in the acid-catalyzed extraction of crude furfural. Extraction time (min), hydrochloric acid concentration (M), and amount of sodium chloride (g) were found to have a significant influence on the extraction yield of crude furfural. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions using ridge analysis were found to be: extraction time 35.0 min, hydrochloric acid concentration 5.0 M, and amount of sodium chloride 7.0 g. Furfural extraction was also performed at optimum conditions to assess the validity of the empirical model. In conclusion, the high furfural extraction yield obtained in our experiments presents an opportunity to harness these unregulated wastes in producing high quality products.


2013 ◽  
Vol 690-693 ◽  
pp. 1029-1032
Author(s):  
Xiao Qiang Li ◽  
Li Juan Lan

Active carbon modified by hydrochloric acid was prepared with impregnation method. The synthesized material was characterized by scanning electron microscopy. It was proved that plenty of pores with diameter of about 5-10μm were exist on the surface of active carbon. The adsorption process with toluene was performed over the modified active carbon to investigate the adsorptive efficiency. For comparison, other porous materials were also performed the adsorption experiment. The results showed that active carbon modified by hydrochloric acid has high adsorptive efficiency for toluene. The results proved that adsorptive performance of active carbon increased with the hydrochloric acid concentration.


1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.


1960 ◽  
Vol 6 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons

The optical densities of suspensions of cells of Halobacterium cutirubrum, H. halobium, or H. salinarium, grown in media containing 4.5 M sodium chloride, increase as the salt concentration of the suspending medium decreases, until a maximum is reached at about 2 M; below this concentration there is an abrupt decrease in optical density. The cells are rod shaped in 4.5 M salt and change, as the salt concentration decreases, through irregular transition forms to spheres; equal numbers of transition forms and spheres are present at the point of maximum turbidity, while spheres predominate at lower salt concentrations. Cells suspended in 3.0 M salt, although slightly swollen, are viable, but viability decreases rapidly with the more drastic changes in morphology at lower salt concentrations. Cells grown in the presence of iron are more resistant to morphological changes but follow the same sequence. Cells "fixed" with formaldehyde, at any point in the sequence, act as osmometers and do not rupture in distilled water although their volume increases 10–14 times. The results indicate that the red halophilic rods require a high sodium chloride content in their growth or suspending medium to maintain a rigid cell wall structure.


2002 ◽  
Vol 68 (8) ◽  
pp. 3965-3968 ◽  
Author(s):  
Patricia A. Shields ◽  
Samuel R. Farrah

ABSTRACT Viruses were characterized by their adsorption to DEAE-Sepharose or by their elution from octyl-Sepharose by using buffered solutions of sodium chloride with different ionic strengths. Viruses whose adsorption to DEAE-Sepharose was reduced most rapidly by an increase in the sodium chloride concentration were considered to have the weakest electrostatic interactions with the solids; these viruses included MS2, E1, and φX174. Viruses whose adsorption to DEAE-Sepharose was reduced least rapidly were considered to have the strongest electrostatic interactions with the column; these viruses included P1, T4, T2, and E5. All of the viruses studied adsorbed to octyl-Sepharose in the presence of 4 M NaCl. Viruses that were eluted most rapidly following a decrease in the concentration of NaCl were considered to have the weakest hydrophobic interactions with the column; these viruses included φX174, CB4, and E1. Viruses that were eluted least rapidly from the columns after the NaCl concentration was decreased were considered to have the strongest hydrophobic interactions with the column; these viruses included f2, MS2, and E5.


Polymer ◽  
1997 ◽  
Vol 38 (20) ◽  
pp. 5247-5250 ◽  
Author(s):  
Gustavo M. Morales ◽  
Marcos Llusa ◽  
Maria C. Miras ◽  
Cesar Barbero

PEDIATRICS ◽  
1962 ◽  
Vol 30 (6) ◽  
pp. 909-916
Author(s):  
Herbert I. Goldman ◽  
Samuel Karelitz ◽  
Hedda Acs ◽  
Eli Seifter

One hundred four healthy premature infants, of birth weight 1,000 to 1,800 gm, were fed one of five feedings: (1) human milk; (2) human milk plus 13 meq/l of sodium chloride; (3) human milk plus 13 meq/l of sodium chloride and 18 meq/l of potassium chloride; (4) a half-skimmed cows milk formula; and (5) a partially-skimmed vegetable oil, cows milk formula. The infants fed any of the three human milk formulas gained weight at a slower rate than the infants fed either of the two cows milk formulas. Infants whose diets were changed from unmodified human milk to the half-skimmed cows milk gained large amounts of weight, and at times were visibly edematous. Infants whose diets were changed from the human milks with added sodium chloride, to the half-skimmed cows milk, gained lesser amounts of weight and did not become edematous. The infants fed the two cows milk diets gained similar amounts of weight, although one diet provided 6.5 gm/kg/day, the other 3.1 gm/kg/day of protein.


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