[en] This paper discusses the method for uranium exploration based on the analysis of helium in water leaching soil samples using ion pump helium detector. Through the research work of comprehensive tests under ten different immersed conditions, an analytical technique for immersing soil samples was estabilshed. The analytical data obtained from soil samples taken from the known buried uranium deposits show that the helium anomalies located directly on bruied uranium deposits with steeply dipping strata. It is demonstrated that the method can be applied to detailed prospecting for uranium deposits

[en] Principle and application results of helium-in-soil measurement in the exploration of concealed collapse pile and prospecting for uranium at depth have been briefly introduced in this paper. A study on characteristics of helium anomaly through five cases indicates that helium content changes remarkably at the margin of collapse pile and its central part. Better helium anomalies appear on the surface of the vertical projection part of uranium ore bodies. It demonstrates that this method may be used to look for concealed collapse pile in the coal mine, to detect karst collapse structure related with mineralization, to prospect for uranium and various kinds of fault structures and to indicate prospective sites of various fault-controlled hydrothermal deposits, to provide the basis for exploration and design

[en] The working principles and the fundamental technical features of IP-1 ion pump helium detector are discussed. Field experiments show that the detector is stable, with high sensitivity and portability. Preliminary results of the hydrogeochemical survey on three different types of known uranium deposits suggest that in proper geological and hydrogeological environments, the expression of deep buried uranium mineralization can be picked up from the hydrogeochemical anomalies

[en] The effect of addition of manganese dioxide into the ore and oxidizing roast pretreatment on acid leaching of uranium by agitation method as well as leached solution by strongly alkaline ion exchange resin D235 adsorption and elution experiments were studied. The experimental results show that: 1) leached slurry filtration property and uranium leaching efficiency of acid leaching can be greatly improved by adding 2%-5% MnO₂ into the ore at 550 ℃ oxidizing roasting; 2) saturated capacity of wet resin D235 can reach to 56.17 mg/ml in high acidic leached liquor; 3) composition of elution reagent is made of 2.05 mol/L NaCl and 0.1 mol/L sulfuric acid, elution contact time is 60 minutes, and elution efficiency is 99.2% by 3 bed volume number elution. (authors)

[en] The exact pH formula about a bicarbonate solution is the theoretical foundation of carbonate leaching of uranium deposits and geological storage of carbon dioxide. Since the existing pH formula about a bicarbonate solution cannot be applied to the lower concentration, especially the micro quantity and trace system, a generalized pH formula is proposed according to the conservation equations of carbonate species and electric charges (or electric neutrality), and its criteria certified for exactness. The calculated results shows (1) The generalized pH-formula meets the demand of exact criteria, and can give the exact value in wide range of concentration of sodium bicarbonate; (2) The minimum and maximum of dissociation degree of bicarbonate are 0.201% and 18.39% respectively, the former is relevant to pH = 8.34 and concentration of sodium bicarbonate beyond 4.5 X 10^-4 mol/L, the latter is pH = 7.0 and infinite dilute solution. (authors)

[en] A generalized pH formula is proposed for the mixed solution of C0₂ and bicarbonate, which are concerned with carbonate leaching of uranium deposit and geological sequestration of C0₂. This method is based on the conservation equations of carbonate species and electric charges (or electric neutrality), and it should describe the effects of the ratio of Co₂ to bicarbonate on pH and composition of solution. The calculating results show that (1) pH of solution decrease with the increase of ratio; (2) Concentration of bicarbonate can be enhanced with addition of carbonate dioxide, (3) pH of solution and concentration of bicarbonate, are related with addition of C0₂ (m) and concentration of sodium bicarbonate (C₀) when C₀ < 0.1 mmol/L, and are related with addition of C0₂ (m) only when C₀ > 0.1 mmol/L. (authors)

[en] Surface states in ZnO nanoparticles play an important role in controlling their electrical transport properties, and these properties can be modified greatly by exposure to UV light. In order to investigate the origin of these effects, we investigate the change in the optical absorption of films of ZnO nanoparticles on exposure to UV light. The modulation spectrum changes from the first derivative to the second derivative of the absorption spectrum as the films are annealed. UV illumination changes the surface states of the nanocrystals, leading to a change in the electric field within the films, which we study using electrostatic force microscopy. The modulation of the optical absorption is found to be consistent with a Stark effect caused by the change in the electric field.

[en] A study on the typical profile of the siliceous breccia-type uranium deposit No.320 conducted by comprehensive geophysical and geochemical exploration indicates that the concealed uranium ore bodies in this kind of deposit possess polarizability anomalies of high values and wide range. The induced polarization sounding can delineate the ore body features such as depth of burial, mode of occurrence and dimension. The IP method is a high sensitive method of prospecting for this kind of concealed uranium deposit. The surface over the ore bodies also occurs geophysical and geochemical anomalies of γ, Po, He, Cu and Mo. On the basis of these composite anomalies, it can be deduced whether these IP anomalies reflect the concealed uranium ore bodies of not so as to greatly raise the capability of the comprehensive exploration. The comprehensive geophysical and geochemical research on anomalous points of same kind out of the ore district No.320 resulted in the discovery of the IP anomalies of high value and wide range in the WBC area. Moreover, geological conditions, anomalies characteristics of regional airborne gamma survey, gravity, hydrochemistry and dispersion halo are also similar with those in the ore district No.320, which is predicted to be a prospective area of concealed uranium deposit

[en] The concept of distributed ISL mining uranium technology and its key equipment are introduced. The technology includes satellite plant's adsorption and central plant's centralized processing technology such as resin washing, elution, acidifying of qualified solution and sediment etc. technology. Key equipment includes load and unload resin adsorption tower at satellite plants, transportation resin tank car and central plant's load and unload resin washing tower, elution tower as well as effluent processing equipment etc. By comparison similar uranium mine technology and equipment home and abroad, the deficiency of distributed ISL mining uranium technology in China and its development direction are pointed out. (authors)

[en] The concept of distributed ISL mining uranium technology and its key equipment are introduced. The technology includes satellite plant's adsorption and central plant's centralized processing technology such as resin washing, elution, acidifying of qualified solution and sediment etc. Key equipment includes load and unload resin adsorption tower at satellite plants, transportation resin tank car and central plant's load and unload resin washing tower, elution tower as well as effluent processing equipment etc. By comparison similar uranium mine technology and equipment home and abroad, the deficiency of distributed ISL mining uranium technology in China and its development direction are pointed out. (authors)