scholarly journals ANALYSIS OF THE LEACHING EFFICIENCY OF INHIBITED WATER AND TANK 23H SIMULANT IN REMOVING RESIDUES ON TANK 48H WALLS

2006 ◽  
Author(s):  
F Fondeur ◽  
T Thomas02 White ◽  
L Lawrence Oji ◽  
C Chris Martino ◽  
B Bill Wilmarth
2021 ◽  
Vol 125 ◽  
pp. 192-203
Author(s):  
Nathália Vieceli ◽  
Raquel Casasola ◽  
Gabriele Lombardo ◽  
Burçak Ebin ◽  
Martina Petranikova

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 230
Author(s):  
Pengcheng Ma ◽  
Hongying Yang ◽  
Zuochun Luan ◽  
Qifei Sun ◽  
Auwalu Ali ◽  
...  

Bacteria–mineral contact and noncontact leaching models coexist in the bioleaching process. In the present paper, dialysis bags were used to study the bioleaching process by separating the bacteria from the mineral, and the reasons for chalcopyrite surface passivation were discussed. The results show that the copper leaching efficiency of the bacteria–mineral contact model was higher than that of the bacteria–mineral noncontact model. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) were used to discover that the leaching process led to the formation of a sulfur film to inhibit the diffusion of reactive ions. In addition, the deposited jarosite on chalcopyrite surface was crystallized by the hydrolysis of the excess Fe3+ ions. The depositions passivated the chalcopyrite leaching process. The crystallized jarosite in the bacteria EPS layer belonged to bacteria–mineral contact leaching system, while that in the sulfur films belonged to the bacteria–mineral noncontact system.


2013 ◽  
Vol 825 ◽  
pp. 107-110
Author(s):  
Sören Bellenberg ◽  
Robert Barthen ◽  
Mario Vera ◽  
Nicolas Guiliani ◽  
Wolfgang Sand

A functional luxIR-type Quorum Sensing (QS) system is present in Acidithiobacillus ferrooxidans. However, cell-cell communication among various acidophilic chemolithoautotrophs growing on pyrite has not been studied in detail. These aspects are the scope of this study with emphasis on the effects exerted by the N-acyl-homoserine lactone (AHL) type signaling molecules which are produced by Acidithiobacillus ferrooxidans. Their effects on attachment and leaching efficiency by other leaching bacteria, such as Acidithiobacillus ferrivorans, Acidiferrobacter spp. SPIII/3 and Leptospirillum ferrooxidans in pure and mixed cultures growing on pyrite is shown.


1981 ◽  
Vol 90 (1) ◽  
pp. 89-93 ◽  
Author(s):  
David W. Johnson ◽  
Robert H. Maisel

Eighty-two cotton, foam, and solid core stock and custom earplugs were evaluated objectively for water absorption and water penetration characteristics in order to determine their efficacy for control of water-borne infection in ears having open middle ear cavities. Cotton plugs, even when saturated with petroleum jelly, had poor consistency in resisting even minimal water pressure. Polymeric foam plugs, especially when saturated with petroleum jelly, appeared to inhibit water flow in conditions approximating actual ear protection use. No plugs evaluated, including custom elastomeric solid core plugs, inhibited water penetration in conditions approximating shallow surface dives. A clinical protocol for evaluation of potential earplugs for patient use is proposed on the basis of this study.


Author(s):  
Jihao Guo ◽  
Hongao Xu ◽  
Bo Li ◽  
Yonggang Wei ◽  
Hua Wang

Abstract Multiple purification of zinc sulfate solution is an important process for zinc hydrometallurgy, and large quantities of copper-cadmium residues are generated as byproducts in this process. Copper-cadmium residues contain a large number of valuable metals that must be recovered. A comprehensive extraction process has been proposed using sulfuric acid as the leaching reagent and hydrogen peroxide as the oxidizing reagent. The effects of acid concentration, leaching temperature, leaching time, liquid-to-solid ratio, hydrogen peroxide dosage and stirring speed on the leaching efficiency were investigated. The optimum conditions were determined as an acid concentration of 150 g/L, liquid-to-solid ratio of 4:1, hydrogen peroxide amount of 20 mL, time of 60 min, temperature of 30 °C, particle size of −d75 μm, and agitation rate of 300 r/min. It was concluded that the leaching efficiency of copper and cadmium reached 97%, but because of the existence of zinc sulfide in the residues, a lower leaching efficiency of zinc was obtained. Furthermore, the leaching kinetics of copper was also studied based on the shrinking core model. The activation energy for copper leaching was 5.06 kJ/mol, and the leaching process was controlled by the diffusion through the product layer.


2018 ◽  
Vol 4 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Daniel Dotto München ◽  
Andréa Moura Bernardes ◽  
Hugo Marcelo Veit

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