Bioleaching of metal from waste stream using a native strain of Acidithiobacillus isolated from a coal mine drainage

In this study, the feasibility of using a biohydrometallurgical technique for selective metals recovery from electronic waste (e‐waste) by bacterial bioleaching was investigated. Acidithiobacillus was identified in coal mining acid mine drainage (AMD). The microorganism was studied using specific sequencing of a 16s rDNA fragment. The potential for the dissolution of copper from waste printed wire boards (PWBs) using the isolated Acidithiobacillus ferrooxidans (A. ferroxidans) was evaluated. The bioleaching experiments were performed in an orbital shaker at 30 °C and 170 rpm, with 10 % (v/v) inoculum and a pulp density of 30 g/L. The copper concentration was determined by energy dispersive x‐ray fluorescence (XRF). The result shows that copper recovery from PWBs using our A. ferrooxidans strain was 95 % after 8 days, which showed the feasibility of this process.     

线路板污泥和电镀含铜废液同时处理回收铜的新工艺

作者开发出一套将线路板污泥和电镀含铜废液同时处理回收铜的新工艺,利用两种含铜废物自身的特性可以节约化工原料的添加,同时可以有效去除COD,以及实现铜和铁等杂质金属的有效分离,对铜的回收率达95%以上并制备出符合饲料级标准的五水硫酸铜,而且无三废排出。     

Recovery of Nonferrous Metals from Metal Finishing Industry Wastes

Abstract

Flexible schemes have been devised for recovery of nonferrous metals (copper, chromium, nickel and zinc) from metal finishing industry waste acids and hydroxide sludges. Evaluations conducted with bench scale experimentation established technical feasibility for adaptations of solvent extraction, precipitation and ion exchange separation processes. It was demonstrated with industrial waste samples that by tailoring several separation stages appropriate for specific waste compositions for complex mixtures of widely varying character that efficient separations can be achieved for copper, chromium, nickel or zinc from contaminant metals such as aluminum, chromium or iron.     

A New Type of Amidoxime-Group-Containing Adsorbent for the Recovery of Uranium from Seawater

Abstract

A new type of adsorbent containing amidoxime groups for the recovery of uranium from seawater was synthesized by the radiation-induced graft polymerization of acrylonitrile onto polymeric fiber followed by amidoximation with hydroxylamine. When amidoxime groups were introduced superficially on the fiber, the amount of uranium adsorbed by the amidoxime groups was higher than that with the amidoxime groups introduced homogeneously in the fiber. The introduction of the poly(acrylic acid) chain and the increase in temperature and flow rate in the adsorption process were effective in increasing the amount of adsorbed uranium. Although alkali metals and alkaline earth metals were found in the adsorbent, the concentration factors for these metals were less than 1/10³ of that for uranium. The present adsorbent had a high stability to various treatments such as contact with alkali and seawater.     

Technetium-99 Removal from Process Solutions and Contaminated Groundwater

Abstract

The predominant form of technetium under oxic conditions is the pertechnetate anion (TcO₄ ^?), which is highly soluble in water and readily mobile in the environment. Technetium-99 is of particular concern because of its persistence and mobility.

Various equipment decontamination and uranium recovery operations at the Portsmouth Gaseous Diffusion Plant generate a “raffinate” waste stream characterized by toxic heavy metals, high concentration of nitric acid, and low levels of radionuclides (²³⁵u and ⁹⁹Tc). Dilution and adjustment of solution pH to a value of 8.2 to 8.5 precipitates a heavy-metals-sludge and a filtrate. The removal of ⁹⁹Tc from these waste streams and from contaminated groundwater can be accomplished using anionic ion-exchange resins.

Batch equilibrium and packed column breakthrough and regeneration studies were performed using inorganic sorbenta and organic ion-exchange resins (Dowex SRB-OH and Reillex resins). These studies were performed on actual and surrogate raw raffinates, filtrates, and surrogate groundwater samples. The experimental conditions were chosen to closely represent the actual process.     

Effect of Shape and Size of Amidoxime-Group-Containing Adsorbent on the Recovery of Uranium from Seawater

Abstract

An amidoxime-group-containing adsorbent for the recovery of uranium from seawater was synthesized by radiation-induced graft polymerization of acrylonitrile onto polypropylene fiber of round and cross-shaped sections. The tensile strength and elongation of the synthesized adsorbent, both of which were one-half those of the raw material, were not affected by the shape of the fiber. The deterioration of the adsorption ability induced by immersing the adsorbent in HC1 was negligible because of the short immersion time required for the desorption with HC1. The concentration factors for uranium and transition metals in 28 days were in the order of 10⁵, while those for alkali metals and alkaline earth metals were in the order 10^?1-10¹. The recovery of uranium with the cross-shaped adsorbent was superior to that of the round-shaped one. XMA line profiles show that the distribution of uranium is much restricted to the surface layer when compared with that of alkaline earth metals. Diminishing the diameter or increasing the surface area was effective for increasing the adsorption of uranium.     

Selective removal of arsenic from arsenic-containing copper dust by low-temperature carbothermal reduction

ABSTRACT

To selectively separate arsenic from arsenic-containing copper dust, this paper reports a new method of treating the dust by carbothermal reduction and roasting it with coke powder at low temperatures. The effects of different roasting temperatures, coke powder additions and roasting times are discussed. Optimum conditions were obtained to selectively separate arsenic from other valuable metals. The volatilization rate of arsenic was 97.02% and the content of arsenic in the slag was 0.31%. Other valuable metals were not volatile under the conditions of a 350°C roasting temperature, coke powder addition of 30%wt, coke powder particle size of 0.15–1 mm, and a roasting time of 150 min.     

Separation and Recovery of Metals from Dilute Solids and Aqueous Phases

Abstract

Present practice for the extraction of metals from low grade dilute ore sources and the recovery of metal values from dilute solutions is reviewed. Special problems associated with extraction from both solid and aqueous phases for copper, gold and silver recovery are considered. Emphasis is directed toward the application of insitu solution mining technology for recovery of metal values in the future.     

Removal of Metal Cations from Water Using Zeolites

Abstract

Zeolites from abundant natural deposits were investigated by the Bureau of Mines for efficiently cleaning up mining industry wastewaters. Twenty-four zeolite samples were analyzed by x-ray diffraction and inductively coupled plasma. These included clinoptilolite, mordenite, chabazite, erionite, and phillipsite. Bulk densities of a sized fraction (-40, +65 mesh) varied from 0.48 to 0.93 g/mL. Attrition losses ranged from 1 to 18% during an hour-long shake test. The 24 zeolites and an ion-exchange resin were tested for the uptake of Cd, Cu, and Zn. Of the natural zeolites, phillipsite proved to be the most efficient, while the mordenites had the lowest uptakes. Sodium was the most effective exchangeable ion for exchange of heavy metals. Wastewater from an abandoned copper mine in Nevada was used to test the effectiveness of clinoptilolite for treating a multi-ion wastewater. The metal ions Fe³⁺, Cu²⁺, and Zn²⁺ in the copper mine wastewater were removed to below drinking water standards, but Mn²⁺ and Ni²⁺ were not. Calcium and NH₄ ⁺ interfered with the uptake of heavy metals. Adsorbed heavy metals were eluted from zeolites with a 3% NaCl solution. Heavy metals were concentrated in the eluates up to 30-fold relative to the waste solution. Anions were not adsorbed by the zeolites.     

CSA Continuous Countercurrent Ion Exchange (CCIX) Technology

Abstract

The CSA-CCIX concept started at ORNL in 1951. It has been adapted to a wide variety of applications worldwide, in water and waste water treatment, fertilizers, hydrometallurgy, and general chemical processing. Unique features and how it works are described. Two extreme applications are described in detail. One is for the extraction of trace amounts of uranium from a copper leach, at 37.85m³/min (10,000 gpm) where very high throughput rates are emphasized. The other is for Acid Retardation, where a strong acid waste is purified and recovered. The feed processing rate here is much lower than the resin rate.     

吸附分离水体中铀的吸附材料研究新进展

铀是最危险的放射性金属之一,广泛存在于核燃料的制备、乏燃料后处理和矿石开采等生产活动所产生的含铀废水中,严重威胁水生生态系统与人类健康。吸附法处理水中的U(Ⅵ)具有便捷高效、经济和选择性好的优势。综述了近3年对水中铀吸附材料的研究新进展,介绍了无机、有机、有机无机复合和生物衍生类吸附材料的制备,结构特点,吸附性能,并对铀吸附材料的研究方向进行了展望。     

Recovery of Metal Values from Low Grade Copper Sulfide Ores

Abstract

In the United States approximately 12 percent of the new copper produced comes from dump leaching of low grade waste rock from open pit mining. While this amount of copper is significant it is unusual, even for massive dumps, for steady-state recovery rates to exceed 20 percent. Basic physical and chemical features important in leaching typical copper porphyry waste rock have been determined in laboratory studies in tests involving up to several tons of waste rock. The important findings of such tests including chemistry of extraction, laboratory modeling, energy implications, and recovery from dilute streams are presented. Special emphasis is given to important rate limiting features of waste rock leaching including the role of autotrophic bacteria in the oxidation sequence. Difficulties in scale up from the laboratory to practice are discussed.     

Design and Cost Studies on the Extraction of Uranium from Seawater

Abstract

For a country like Japan, which has very limited energy resources, nuclear power generation is an attractive energy option. However, since known domestic resources of uranium are limited, it is desirable to develop less-conventional uranium sources. To investigate the technical and economic feasibility of extracting uranium from seawater, a research program has been carried out since 1975 by the Metal Mining Agency of Japan, under sponsor-ship of the Ministry of International Trade and Industry. The program includes studies in the following research areas: chemical process selection, adsorbent development, continuous adsorption and elution performance, eluate recovery by steam stripping or electrodialysis, and secondary concentration of uranium in the eluate. Several site selections around the Japanese coast have been examined along with a comparison of various seawater contacting structures. Conceptual designs and tentative cost estimations have been conducted on two types of commercial plants: pumping and fixed bed, and direct sea current utilization. This paper summarizes the conceptual design and cost estimation results.     

铜尾矿建材化应用研究现状及矿物组成影响作用规律

我国铜尾矿排放及储量巨大,造成环境污染和资源浪费。铜尾矿矿物成分复杂、颗粒粒度较细等问题限制了铜尾矿的高效高附加值利用。本文综述了铜尾矿的矿物属性、物理化学性能特征及其在建材化应用过程中的技术和控制要求,从铜尾矿用于蒸压加气混凝土、水泥基材料、水泥熟料、砖、微晶玻璃、多孔材料、充填材料等多个途径,总结了铜尾矿的主要应用方式、作用特征和主要成分的影响作用规律。为铜尾矿等固废生产型企业协同建材行业系统解决尾矿资源化问题提供参考,协同建材行业的发展方向和产品要求,提出了未来尾矿资源建材化处置的关键性问题,为真正实现尾矿的产品资源化利用提供支持。     

铜酞菁生产废酸废水综合治理方案探讨

某铜酞菁生产企业将产生的废酸、废水混合后采用生化处理法,其处理成本高、运行效果差。通过调查废酸、废水的来源、水质、水量,提出废酸回收、酞菁蓝漂洗水压滤回用及混合废水的资源化三项方案。方案不但减少了原料消耗、治理了废酸废水,而且回收了高价值铜泥,同时利用废酸吸收生产工艺中的高含氨废气,生产副产品硫酸铵,实现了废物的资源化利用,达到了以废治废的目的,符合循环经济的理念。     

Kinetics of Adsorption of Uranium on Amidoxime Polymers from Seawater

Abstract

Distributions of uranium adsorbed on amidoxime polymers crosslinked with tetraethyleneglycol dimethacrylate (4EGDM) and/or divinylbenzene (DVB) from seawater were examined by x-ray microanalysis in order to elucidate the diffusion behavior of uranium into the polymer matrix. The uniform distribution of the ligands on the polymers was confirmed by the distribution of Cu(II) adsorbed from copper(II) dichloride solutions. It was found that the distribution of uranium adsorbed is changed significantly by the composition of 4EGDM and DVB. Thus, the polymer crosslinked with 4EGDM exhibits a uniform distribution of uranium; however, as the ratio of DVB to 4EGDM increases, a more predominant distribution of uranium near the periphery of the polymer particle appears and the intensity decreases. This suggests that the adsorption rate of uranium is governed by the diffusion of uranium into the polymer matrix, explaining well the dependence of the adsorption rate on the hydrophilicity of the polymer. On the basis of these results, the diffusion constant of uranium into the polymer matrix was estimated to be 3.3 × 10^?-7 cm²/s.     

Status of Technology for the Recovery of Uranium from Seawater

Abstract

Experimental work involving recovery of uranium from seawater is currently under way in several countries. Hydrous titanium oxide has been repeatedly identified as the most promising candidate adsorbent. However, many of its properties such as distribution coefficient, selectivity, loading, and possibly long-term stability may be inadequate for a practical recovery system. Also, evaluations of the energy efficiency of pumped or tidal power methods of contacting the seawater with the hydrous titanium oxide are in major disagreement. Published estimates of the cost of recovering U₃O₈ vary by an order of magnitude. Needed future research and development activities are defined, based on a literature review of the available chemical information. The prime recommendation is for a fundamental laboratory chemical development program to achieve improved absorbent properties, either with hydrous titanium oxide or other materials. Some unresolved engineering aspects of uranium recovery from seawater are also identified.     

Recovery of Uranium from Seawater

Abstract

Seawater contains various elements in solution. Deuterium, lithium, and uranium are the important ingredients for energy application at present and in the future. This paper deals with the recovery of uranium from seawater, with emphasis on the development of an adsorbent with high selectivity and rate of adsorption for uranium.

Polyacrylamidoxime chelating resins were synthesized from various co-polymers of acrylonitrile and cross-linking agents. The resulting resins with the chelating amidoxime group showed selective adsorption for uranium in seawater. The amount of uranium adsorbed from seawater at room temperature reached 3.2 mg/g resin after 180 days.

Polyacrylamidoxime fiber, which was prepared from polyacrylo-nitrile fiber and hydroxylamine, showed a high rate of adsorption for uranium. The polyacrylamidoxime fiber conditioned with 1 M HCl and 1 M NaOH adsorbed 4 mg U/g fiber from seawater in ten days.     

Separation and Recovery of Uranium,Neptunium, and Plutonium from High Level Waste Using Tributyl Phosphate: Countercurrent Studies with Simulated Waste Solution

ABSTRACT

The present work deals with countercurrent extraction studies on the partitioning of uranium, neptunium, and plutonium using 30% tributyl phosphate (TBP) from simulated high level waste solution generated during reprocessing of spent uranium fuel from pressurized heavy water reactors. The oxidation states of neptunium and plutonium were adjusted either by 0.01 M potassium dichromate or 0.01 M dioxovanadium ion. Neptunium and plutonium, extracted in the TBP phase, were stripped together using a mixture containing 0.05 M ascorbic acid and 0.25 M hydrogen peroxide in 2.0 M nitric acid solution. Although dioxovanadium ion is more effective for proper adjustment of the oxidation states of plutonium and neptunium, subsequent recovery of these actinides from loaded TBP is better if potassium dichromate is used for the valency adjustment. Results of the stagewise analysis of extraction and stripping of actinides using mixer-settlers are presented.     

Recovery of Uranium from Seawater: A Review of Current Status and Future Research Needs

The recovery of uranium (U) from seawater has been investigated for over six decades in efforts to secure uranium sources for future energy production. The majority of the research activities have focused on inorganic materials, chelating polymers, and nanomaterials. Previous studies of uranium adsorption from aqueous solutions, mainly seawater, are reviewed here with a focus on various adsorbent materials, adsorption parameters, adsorption characterization, and marine studies. Continuous progress has been made over several decades, with adsorbent loadings approaching 3.2 mg U/g adsorbent in equilibrium with seawater. Further research is needed to improve first, the viability including improved capacity, selectivity, and kinetics, and second, the sorbent regeneration for multicycle use. An overview of the status of the uranium adsorption technology is provided and future research needs to make this technology commercially competitive are discussed.