Electro-chemical behaviour of different metals in Sodium Chloride solution

Leaching of copper from a Jordanian copper ore has been studied using a stirred batch reactor with hydrochloric acid as the main lixiviant, under the following conditions: temperature 25 -45 o C, acid concentration 0.05 -0.2 N, particle size 462 -1850 m, stirring speed of 700 -1000 rpm, and solid/liquid ratio of 1 -4 g/L. It was found that the rate of leaching of copper ore with hydrochloric acid or sulfuric acid, increases with temperature and acid concentration, while it decreases with increasing particle size. At the same operating conditions, leaching with sulfuric acid gave slightly greater conversion than leaching with hydrochloric acid, particularly at operating conditions of high temperature, high acid concentration, and small ore particle sizes. A maximum copper dissolution of about 87 % can be recovered at a leaching temperature of 45 o C, 462 m particle size, 0.2 N hydrochloric acid, 1.0 g/L solid to liquid ratio, and 1000 rpm stirring speed. Keeping all these operating parameters constant while decreasing the hydrochloric acid concentration to 0.05 N will decrease the copper dissolution to 83 %. On the other hand, decreasing the leaching temperature to 25 o C while keeping the other parameters fixed at 0.2 N, 1.0 g/L solid to liquid ratio, 1000 rpm stirring speed, and a particle size of 462 m decreases the copper dissolution to 80 %.

Section: Introductionmentioning

confidence: 99%

Leaching of Copper Ores: Effects of Operating Variables

Mubarak¹

2020

“…The main advantages of root piles: Manual earthworks are completely excluded. Drilling wells is carried out directly through the foundation, without affecting communications that pass near buildings and in basements [7].…”

Section: Resultsmentioning

confidence: 99%

Strengthening Technologies of Different Types of Foundations in Buildings

O.T¹

2020

Innovative technologies in the construction industry have taken a firm position in the construction-engineering sector. The article discusses the new technologies used for strengthening the foundations of different types. A study on the traditional method of strengthening foundations has been carried out and indicators of new technologies use are presented. Traditional options for strengthening foundations by increasing the foundation base are considered, from the point of view of geotechnics and manufacturability in relation to loose and saturated soils. The operational characteristics of new technologies during the work on strengthening the foundations are given.

“…The optical properties of samples of silicon doped with nickel were studied using spectral instruments of the near and middle IR ranges (0.75-25 μm) [1]. A similar work investigated by Y. Pratapa et al [9], where electro-chemical behavior of various metals is studied .In the studies, we used a method used by Fujimoriet.al [10], where single-crystal silicon samples with a dislocation density of 5 × 10 13 ÷ 10 15 cm -3 with an initial concentration of phosphorus impurities. The concentration of IR active oxygen in these samples was (1÷8) 10 17 cm -3 , and carbon ~ 10 17 cm -3 .Nickel was introduced by diffusion at temperatures of 1100 ÷ 1250 ° C. The effect of the temperature of diffusion and low-temperature treatment on the absorption spectrum at room and nitrogen temperatures was investigated.…”

Section: Methodsmentioning

confidence: 99%

Electrophysical properties of Silicon doped by Nickel impurity using Diffusion method

Utamuradova¹

2020

Silicon is a mature material, but it is still unique for its crucial role in the microelectronic and photovoltaic sectors. Despite the vast knowledge accumulated on silicon and their alloys, this material still demands research. In this paper, the conductivity and lifetime of non equilibrium charge carriers of nickel impurities in single-crystal silicon are determined. The electrophysical properties for the silicon single crystals doped with nickel impurity by establishing optimal diffusion mode were studied with the Hall effect method and the standard method in constant electric and magnetic fields. It is shown that the generation of thermal donors is suppressed by the interaction of nickel and oxygen impurities introduced at 500 ° C, and it is proved that it does not affect the formation of high-temperature thermal donors formed at 700 ° C.