Effects of γ radiation on the leaching kinetics of various nuclear waste-form materials

Nature ◽  
1982 ◽  
Vol 300 (5890) ◽  
pp. 339-341 ◽  
Author(s):  
Aaron Barkatt ◽  
Alisa Barkatt ◽  
William Sousanpour
Keyword(s):  
Nuclear Waste ◽  
Waste Form ◽  
Leaching Kinetics ◽  
Γ Radiation ◽  
Kinetics Of

Radiatio Damaae Growth Models for the Interpretation of Radiation Effects on Nuclear Waste Form Leaching

1983 ◽  
Vol 26 ◽  
Author(s):  
A. M. Ougouag ◽  
A. J. Machiels
Keyword(s):  
Free Surface ◽  
Ion Implantation ◽  
Radiation Damage ◽  
Nuclear Waste ◽  
Radiation Effects ◽  
Growth Models ◽  
Waste Form ◽  
Damage Growth ◽  
Kinetics Of ◽  
Existing Data

ABSTRACTTwo approaches for modeling radiation damage growth are presented and evaluated in the light of existing data. It results that purely geometric and statistical considerations about the distribution and overlap of damage are insufficient for accounting for the differences observed in leaching data from ion implantation and actinide doping experiments. It is shown, however, that the incorporation of effects such as those induced by the proximity of a free surface and the directionality of the irradiation into the kinetics of radiation damage ingrowth has the capability for accounting for the differences.

Study on leaching kinetics of hexavalent chromium from aged calcium-free chromium slag

2021 ◽  
pp. 1-13
Author(s):  
Quan Qi ◽  
Liang Li ◽  
Liangyu Wei ◽  
Baoming Hu ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Resource Utilization ◽  
Scientific Basis ◽  
Diffusion Reaction ◽  
Leaching Kinetics ◽  
Leaching Rate ◽  
Chromium Slag ◽  
Leaching Solution ◽  
Main Components ◽  
Kinetics Of

To provide a scientific basis for the resource utilization of chromium slag, this article studies the release law of hexavalent chromium in the aged calcium-free chromium slag. XRD (X-ray diffractometer) and MLA (Mineral Liberation Analyzer) were used to analyze the composition of the chromium slag; using sulfuric acid-nitric acid as the leaching solution, the release law of hexavalent chromium in chromium slag and the leaching kinetics were studied. The results show that main components of the chromium slag are magnesioferrite, chromite, hematite, hydrargillite, and spinel; chromium is mainly present in chromite and magnesioferrite; the leaching rate of hexavalent chromium increases with the increase of temperature or the decrease of pH. The analysis of leaching kinetics shows the leaching rate is controlled by the internal diffusion reaction, and the apparent activation energy is 11.93 kJ·mol–1. The chromium slag is aged in high temperature seasons, which is conducive to the precipitation of hexavalent chromium in the chromium slag, can increase the yield of chromate in the roasting kiln, and is conducive to resource utilization; chromium slag should be stored in order to prevent acid rain erosion which leads to environmental pollution risk (e.g. drinking water).

Leaching kinetics of copper and valuable metal extraction from copper-cadmium residues of zinc hydrometallurgy by oxidation acid leaching

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jihao Guo ◽  
Hongao Xu ◽  
Bo Li ◽  
Yonggang Wei ◽  
Hua Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Metal Extraction ◽  
Agitation Rate ◽  
Leaching Kinetics ◽  
Solid Ratio ◽  
Zinc Hydrometallurgy ◽  
Kinetics Of ◽  
Leaching Efficiency

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.

Leaching kinetics of colemanite in potassium hydrogen sulphate solutions

2012 ◽  
Vol 18 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Rövşen Guliyev ◽  
Soner Kuşlu ◽  
Turan Çalban ◽  
Sabri Çolak
Keyword(s):  
Leaching Kinetics ◽  
Potassium Hydrogen ◽  
Hydrogen Sulphate ◽  
Kinetics Of
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