Resin-in-pulp Research Articles

Developing a mini pilot resin in solution Process for adsorption of uranium in Pachuca reactors (case study: Saghand uranium ore of the Central Iran)

Resin in pulp, as the most frequently employed process for extraction of uranium from low-grade ores, encounters difficulties when the pulp contains dense or abrasive minerals, e.g., Saghand ores in central Iran. To overcome these complications, it was suggested to remove solid content of the pulp at first, and inject the clear solution into a cascade of Pachuca reactors, where uranium is adsorbed by an anion exchanger such as Varion-AP. We made two mini pilot cascades, each comprising ten Pachuca reactors, to check both co-current and countercurrent resin in solution processes on the Saghand leach liquor. The countercurrent scheme, having a higher efficiency, was able to adsorb 99% of uranium from a 238 mg/L solution, with 7 stages, at optimum pH = 1.8. Kinetics of adsorption was controlled by intra-particle diffusion, and a generalized Glueckauf model, fairly well described multistage adsorption. The most significant process variable was found to be flow rate of the resin, whose precise adjustment, results in the optimum process design, where the net present value (NPV) becomes minimum.

Conservation of the Lacquer Artifacts Excavated from Suchon‐ri, Gongju, Korea

In November 2011, various artifacts were excavated from the No. 8 stone-lined tomb in Suchon-ri, Gongju by the Chungnam Institute of History and Culture. These included artifacts with lacquered mainframe and silvery metal ornament. These were recovered together with soil and underwent conservation treatment. In this paper, we discuss the scientific analysis and conservation treatment of the lacquered artifacts excavated from the Suchon-ri site. Among our findings is that the artifacts have three layers of lacquer coating and the metal parts are primarily composed of Ag. As the artifacts were recovered with soil from the site, the soil was removed from underneath and inside the artifacts. The inside of the lacquerware was reinforced with rayon paper using 3% funori, and the metal was treated with acrylic resin after removing the acrylic resin previously used to recover the artifact, followed by cleaning. The metal was also internally reinforced with gauze. Finally, the interior reinforcement was made using PVA and resin in pulp and attached with funori to preserve the shape of the lacquerware, and the exposed rayon was finished with acrylic paint. The main advantages of this study are its review of conservation treatment strategies for lacquer artifacts whose numbers have recently increased, and the application of new conservation treatment methods.

Rapid Leaching of Synthetic Scheelite by a Resin-in-Pulp Process

Extraction of tungsten from scheelite has attracted considerable attention due to the progressive exhaustion of wolframite. This work presents a resin-in-pulp (RIP) technique to extract tungsten from synthetic scheelite. Decomposition of scheelite and extraction of tungsten from the leaching solution were achieved simultaneously by using diluted acid with 310 resin. The effects of the pH value of the acid solution, temperature, liquid-to-solid ratio, and resin dose on the scheelite leaching were investigated. The results showed that more than 96% of tungsten could be extracted. Furthermore, tungsten loaded on anion resin was effectively desorbed by using NH4OH as desorbent, and under the optimal desorption condition, the desorption efficiency reached up to 98.37%. Kinetic study suggested that the extraction of tungsten by the RIP technique could be fit using the Avrami kinetic model equation and was a chemical-controlled process. This work demonstrates that RIP can provide an effective way to extract tungsten from scheelite.

Analytical and semi‐analytical kinetics models for design and optimization of double‐resistance resin in pulp and carbon in pulp processes with both reversible and irreversible nature

AbstractThe current study was aimed at developing a package of “model + algorithm” for the design of resin in pulp (RIP) and carbon in pulp (CIP) processes of gold, uranium, and base metals. For this purpose, we first formulated a double‐resistance model for irreversible adsorption (accompanied by chemical reaction) in CSTRs, and modified the McKay et al. semi‐analytical model for reversible uptake in a similar system. We then devised two algorithms for the design and optimization of reversible and irreversible RIP and CIP cascades. The developed algorithms were applied on the extraction of copper, uranium, and gold. The packages are able to specify the optimum number of stages, reactor volume (V), resin flow rate (m.), and resin hold up (φs). This shows an evident advantage over the McCabe‐Thiele method, whose only result is the number of stages. The new methods have only two adjustable parameters of diffusivity (Deff) and liquid film coefficient (k), whose determination can be carried out through simple batch experiments. As an additional work, this study also presents a method for mathematical troubleshooting for the Mc Kay et al. model.

Enhanced ionic exchange of uranium by indirect ultrasonic application with a submerged ultrasound probe

With the final goal of ultrasonic application to ion exchange in a resin-in-pulp (RIP) system, the feasibility of an indirect ultrasonic application with a submersed ultrasonic probe was investigated first for the enhancement of ion exchange in the following resin-in-solution (RIS) system: Lewatit MonoPlus MP 600XL in an artificial solution with 106 ppm uranium. Ultrasonic radiation enhanced the ion exchange efficiency without mechanical degradation of resin. For 3.6 g/L of resin, the enhancement was 79 percent after 10 min of ion exchange and it gradually decreased to 11 percent at 60 min. In addition, a preliminary test of the mechanical stability of the resin in the RIP system showed little mechanical fracture of the resin due to ultrasound, which indicates that indirect ultrasonic application by a submersed ultrasonic probe is applicable for RIP systems.

Modeling and Process Design of Intraparticle Adsorption in Single-Stage and Multistage Continuous Stirred Reactors: An Analytical Kinetics Approach

Continuous adsorption in stirred reactors in the form of carbon in pulp (CIP) and resin in pulp (RIP) is an established process for the extraction of gold and uranium. Under the circumstance of intraparticle diffusion resistance, CIP and RIP have been accurately modeled by the Boyd’s series (reversible adsorption) and shrinking core model (irreversible adsorption). The present study, in its first part, introduces an analytical formula that most closely approximates both models. Using such formula, the study addresses a basic algorithm for optimization of single-stage continuous adsorption systems through linking of the major process variables. Furthermore, this study is devoted to developing an “analytical kinetics approach” for the design of multistage CIP and RIP processes via application of Glauekauf’s multiple series. Advantages of the new approach over the McCabe–Thiele “Equilibrium Approach” are (1) the incorporation of the kinetics and equilibrium into one unified model, and (2) accurate determination of the number of stages, reactor size, and optimum operational conditions.

Studies on the separation of dissolved uranium from alkaline carbonate leach slurries by resin-in-pulp process

The increasing demand for uranium fuel for energy generation has triggered interest in the exploitation of various resources including lean tenor ores and tailing dumps which are otherwise considered uneconomical till recently. The process-schemes of new plants are incorporating several new technologies such that the process is economically attractive and eco-friendly. One such development catching the lime-light in uranium ore processing industry everywhere is the resin-in-pulp (RIP) technology. This paper describes the results of laboratory studies on the recovery of dissolved uranium values from an alkaline leach slurry of a medium-grade uranium ore from Gogi (Karnataka, India) using the resin-in-pulp (RIP) process. Besides anionic carbonate complex of uranium – [UO2(CO3)3]4−, the other major anionic constituents of the leach solution are CO32-, HCO3−, SO42-, Cl−, PO43- and MoO42-. The total dissolved solutes (TDSs) are about 45g/l. Various commercially available strong base anionic type resin-in-pulp (RIP) grade resins – both macro-porous and gel type, were studied with respect to their loading capacity. The gel type polystyrene based resins grafted with quaternary ammonium ion gave superior loading capacity in comparison to macro-porous resins. Parametric variation studies for optimizing the other process conditions, including adsorption kinetics, were then carried out on the short-listed resin. Results of the semi-continuous counter-current extraction and elution tests indicated that about 98% of the dissolved uranium values can be recovered during the loading process and practically the entire loaded uranium can be eluted using NaCl eluant.

Recovery of nickel and cobalt from laterite leach tailings through resin-in-pulp scavenging and selective ammoniacal elution

In the hydrometallurgical processing of nickel laterite ore, a significant amount of dissolved nickel and cobalt can be lost to neutralized tailings slurry during counter current decantation. Resin-in-pulp (RIP) scavenging using ion exchange resin functionalized with iminodiacetic acid (IDA) has been proposed as an effective way to recover lost metal value. However, the tendency of this resin to co-load impurities makes integration of metal value back into the plant challenging. In this paper, the application of bis-picolylamine functionalized resin to RIP scavenging is explored. Both types of resin load the valuable metals effectively but bis-picolylamine functionalized resin has a much lower affinity for unwanted impurities. After loading, selective elution of nickel and cobalt from the new resin was carried out using an ammonia based eluent. The resultant eluate was high in nickel and cobalt with ppm levels of impurities, making it appropriate for downstream integration in existing nickel/cobalt refineries.

Effect of hydrophilic substances in spruce TMP resin on its physico-chemical characterization and deposition tendency

The viscosity, wettability and deposition tendency of spruce thermomechanical pulp resin extracted with hexane, acetone and hexane–acetone (9:1, v/v) were studied in this paper. Some hydrophilic substances such as sugars and lignans could be extracted by some hydrophilic solvents, and the effect of the hydrophilic substances on physico-chemical properties is still not well known. The results showed that hydrophilic substances such as lignans and sugars present in spruce thermomechanical pulp resin had a great effect on resin physico-chemical properties. About 19% sugars and 14% lignans were identified in the acetone extracts, which could increase resin viscosity greatly. Only a little of lignans and sugars could be extracted by hexane–acetone, but these sugars and lignans could increase resin hydrophilicity evidently, leading to the decrease in contact angles with water and the increase in the acid–base component of work of adhesion. During preparation of resin dispersions, however, these sugars and lignans dissolved in dispersions could pass through the pores of the dialysis tube into water system which would cause an unexpected deposition result of the acetone-extracted resin dispersion. Resin extracted with hexane can be regarded as a relative ideal resin model in evaluating resin deposition tendency.

Recovery of rhenium from molybdenite calcine by a resin-in-pulp process

This paper introduces a resin-in-pulp (RIP) hydrometallurgical process, which is widely used in gold leaching and recovery industry, to recover rhenium effectively and economically from molybdenite calcine by leaching, absorbing and eluting operations. With fresh water leaching and strong basic anion resin absorbing simultaneously, followed by NH 4OH and HNO 3 eluting Mo and Re respectively, more than 90% of rhenium was recovered. Factors influence leaching such as leaching time, ratio (wt/wt) of solid to liquid in the pulp, ratio (v/v) of resin to the pulp as well as parameters affecting the absorbing and eluting processes are discussed. The new RIP rhenium recovery process obtained is of the advantages of higher selectivity, short process, less costs and environmental compact, which is beneficial to the molybdenum and rhenium industries to comprehensive utilize their less common metals resource.

The development of a resin-in-pulp process for the recovery of nickel and cobalt from laterite leach slurries

Up to 10% of the soluble nickel and cobalt can report to the tailings of a pressure acid leach (PAL) process for the recovery of nickel from lateritic ores as a result of the difficulties associated with the poor settling characteristics of the autoclave discharge. This paper describes the results of laboratory and pilot-plant investigations aimed at establishing the potential for the application of a resin-in-pulp (RIP) process to improve the overall nickel and cobalt recoveries from such tailings. Small-scale batch tests in the laboratory established the technical feasibility and this was followed by several campaigns using a continuous six-stage miniplant which demonstrated that the process could achieve the desired results and which enabled a pilot plant to be designed. The integrated pilot plant operated on site at a local plant over a period of several months. The paper will discuss the results from this testwork, which has culminated in a preliminary process design for a full-scale plant. In addition, the more fundamental aspects associated with the adsorption and elution processes have been investigated and process models developed for these operations.

Recent advances in the development of an alternative to the cyanidation process: Thiosulfate leaching and resin in pulp

A process based on thiosulfate leaching followed by resin-in-pulp gold extraction was developed to treat the carbonaceous, preg-robbing ores of Barrick’s Goldstrike orebody in the Carlin Trend of Nevada. These ores have proven to be amenable to thiosulfate leaching under mild conditions. Gold leaches rapidly as the gold thiosulfate complex, which, because of its low affinity for graphitic carbon, does not suffer the preg-robbing phenomenon that is a feature of these ores in cyanide leach circuits. The mild leaching conditions are also compatible with a gold-recovery process involving direct recovery from the leach pulp by adsorption on strong-base anion-exchange resins. Finally, a novel elution/regeneration process was developed to elute the gold off the resin, recover the gold from the eluate and restore the resin for recycling to the adsorption circuit.

Modification and preparation of polymeric adsorbents for precious-metal extraction in hydrometallurgical processes

This paper describes the efforts made to develop polymeric adsorbents that could be applied to the recovery of precious metals (Au, Pt, Pd and Rh) from cyanide leaching solutions. The polymeric adsorbents prepared should fit they following criteria: be compatible with the nature of the leaching solutions concerned; have good selectivity patterns against the other metal cyanides; have good elution properties and be compatible on integrated systems of leaching and extraction (resin-in-pulp (RIP) and resin-in-leach (RIL)). Knowledge of the chemical speciation of the target metals in the leaching solutions to be treated and the nature and structure of the metal complex to be extracted is very important in understanding the metal-extraction reactions and selectivity factors. As selectivity patterns are greatly influenced by the polymer structure, ionic density and hydrophilic/hydrophobic nature of the polymeric supports, the definition of the structure and functionality of the polymeric supports has been based on the chemical speciation as one of the more effective options fbr polymer support selection. Two methods have been used in selecting polymeric adsorbents: commercial ion-exchange resins and ion-exchange impregnated resins prepared by physical immobilisation of selective and specific reagents used, in solvent extraction onto high surface polymeric materials. Both types of material were evaluated in two applications: extraction and recovery of gold cyanide from leaching liquors and recovery of Pt, Pd and Rh from leaching solutions obtained on cyanidation steps of automobile catalytic converters. The introduction of both polymeric materials is directed towards the selective recovery of gold and precious metals (Pt, Pd, Rh) as an alternative to defined processes based on adsorption steps by activated carbon and/or precipitation by thermal processes.

Factors affecting the mechanism of the adsorption of arsenic species on activated carbon

The development of carbon-in-pulp (CIP) and resin-in-pulp (RIP) processes sparked off intensive investigations into the kinetics and mechanism of adsorption of various species onto activated carbon. The increased processing of complex sulphide ores (e.g. the bacterial oxidation of gold-bearing arsenopyrite) has led to higher levels of impurities such as arsenic in process streams. The removal of such impurities could become a new field of application for activated carbon. It was found that As(V) is more effectively removed from solution by using activated carbon with a high ash content. Pretreatment of the carbon with Cu(II) solutions improves its arsenic removal capacity. The optimum pH for arsenic adsorption by pretreated carbon is approximately 6. There are two mechanisms of arsenic adsorption which occur simultaneously. The arsenic in solution can form insoluble metal arsenates with the copper impregnated in the carbon. Arsenic is also adsorbed independently of the impregnated copper. Ion pair formation has been ruled out in the latter case. Arsenic desorption is easily achieved using strong acidic or alkaline solutions. When acidic solutions are used, copper is also eluted.

5356517 Hydrolysis of resin in pulp with an enzyme and a peroxide : Pedersen Lars S; Skjold-Jorgensen Steen Lyngby, Denmark Assigned to Novo Nordisk A/S; SCA Wifsta-Ostrand

5356517 Hydrolysis of resin in pulp with an enzyme and a peroxide : Pedersen Lars S; Skjold-Jorgensen Steen Lyngby, Denmark Assigned to Novo Nordisk A/S; SCA Wifsta-Ostrand

5356517 Hydrolysis of resin in pulp with an enzyme and a peroxide : Lars S Pedersen, Steen Skjold-Jorgensen, Lyngby, Denmark assigned to Novo Nordisk A/S; SCA Wifsta-Ostrand

5356517 Hydrolysis of resin in pulp with an enzyme and a peroxide : Lars S Pedersen, Steen Skjold-Jorgensen, Lyngby, Denmark assigned to Novo Nordisk A/S; SCA Wifsta-Ostrand

Review of gold extraction from ores

Australia is now an important gold producer in the world. The nature of Australian gold production is briefly reviewed and the hydrometallurgy of gold extraction is considered. The choice of processing routes for free milling, complex and refractory ores is discussed. For free milling ores, cyanidation and recovery by the Carbon-in-Pulp/Carbon-in-Leach process (CIP/CIL) is the primary and proven treatment process. Copper containing ores are discussed in some detail as they interfere in the CIP/CIL process. Oxygen consuming and preg-robbing ores are also described. Five different classes of process options for pretreating refractory ores are considered in detail. These options include: ultrafine grinding; acid and alkaline pressure oxidation; and a variety of chemical pretreatments such as: Activox process, HMC process and Electrolytic oxidation process. In Australia, the two pre-eminent options for refractory gold ore pretreatment are roasting and biooxidation and this development is reported. The trial of pressure cyanidation of stibnite concentrates at the Golden Spec mine in Australia is described. Pyrolysis, the Nitrox/Redox process, the Artech/Cashman process and the Caro's acid process have not gained commercial status so far. The potential for resin-in-pulp (RIP) to replace CIP/CIL is discussed. The use of cyanide has generated environmental concerns because of its toxicity and therefore research on alternative gold recovery processes using non-toxic reagents is considered. The key candidates are: ammoniacal thiosulphate, thiourea and halide solutions. The chemistry of these leaching systems is briefly described and proposed flowsheets are referenced. The future prospect for biohydrometallurgical gold recovery is indicated.

Modern trends in gold processing — overview

This paper reviews the state of the art in processing and extraction of gold. The ore bodies which were considered uneconomical at one time are becoming economical due to new and advanced methods of extraction. The paper discusses the gold treatment methods on free milling ores with conventional cyanidation and refractory ores with direct and pretreatment techniques for the recovery of high gold values. In the extraction aspect, the paper discloses two different extraction schemes on treating refractory ores, namely pretreatment followed by gold leaching and direct leaching. Pretreatment process involving roasting chemical oxidation and bio-oxidation have been discussed. Direct leaching of gold ores such as heap leaching, carbon in pulp (CIP), carbon in leach (CIL) and resin in pulp (RIP) are summarized. This paper also dicloses in a detailed manner the research approach on the development of alternative leach reagents which could improve environmental concerns as compared to the use of cyanide. Special emphasis of the review is focussed on the technical and economic guidelines for developing a small gold mine on the basis of capital and operating cost analysis.

Developments in Gold Leaching: A Literature Survey

The gold industry has seen intense activity in the areas of exploration and metallurgy'in recent years. Many developments have taken piace through which ore bodies that were once considered uneconomical to exploit are becoming economical grade. Even the traditional cyanidation process has been modified during the course of time to make it more economical and efficient. Developments such as heap leaching, in-situ leaching, carbon-in-pulp (CIP), carbon-in-leach (CIL) resin-in-pulp (RIP), and pretreatment of refractory ores have already made an impact on gold industries. Research and development work is also being carried out on less toxic, more efficient lixiviants which may eventually replace the toxic cyanide, solving the disposal problem currently facing the industry. This paper aims at summarizing the developments in the extraction of gold using conventional, as well as unconventional, lixiviants. Some developments in the area of gold recovery from pregnant solutions have also been briefly discussed.

Pitch Problems in Board-making Mills

The tendency of pulp resin particles to coagulate and then adhere to wire and fibrous surfaces causes what is generally known in the paper industry as “pitch trouble”. This is almost specific to the production of pulp and paper from woods by sulfite process or kraft process, but it can occur to an equal degree in mills handling waste papers. An attempt was made to obtain some fundamental knowledge on the reduction of pitch-causing potential through chemical analysis of the pitch samples obtained in boardmaking mills. The result has indicated that the major components of deposited pitch are lignin substances and neutral resin compounds existing in pulp, and resin ous polymers originally located in the waste papers. This would imply that the pitch-causing potential of these waste papers would be no less than that of pulp material. A few methods which would contribute to the control of pitch problems encountered in board manufacture have been suggested on the basis of numerical figures obtained from pitch analysis.