Innovative technology for processing saprolitic laterite …
The development of a hydrometallurgical hydrochloric acid based leaching process for the treatment of nickeliferous laterites of various types is described. ... of hydrochloric acid by pyrohydrolysis with by-product recovery of magnesia some of which might be used for acidity control in the process. Attempts to leach successive batches …
Hydrochloric Acid Leaching of Philippine Coal Fly Ash: …
Coal Fly Ash (CFA) is a hazardous waste from coal-fired power plants, but has increasingly become a popular supplementary cementitious material for cement in the construction industry. As a secondary resource of REE, its main advantage lies in its fine particle size that eliminates the need for costly and energy-intensive comminution. In this …
Single-Step Hydrometallurgical Method for the Platinum …
Abstract Platinum group metals (PGMs) are considered critical raw materials, thus their recycling and re-use is of outmost importance. Among the PGMs, platinum (Pt), palladium (Pd) and rhodium (Rh) are the basic metals used in catalytic converters. Concerning the stringent EU standards for emission control imposed to car …
Novel Methods for Bastnaesite Concentrate Leaching
The modern process for this is a hydrochloric acid leach stage followed by a caustic crack leach stage as used at the Mountain Pass Mine in California. ... in order to bring this novel process to industrial scale, the system needs to be optimized for acid use, fluoride control, solid–liquid separation after leaching, and the ability for the ...
A Hydrochloric Acid Process for Nickeliferous Laterites
The development of a hydrometallurgical hydrochloric acid-based leaching process for the treatment of nickeliferous laterites of various types is described. A key step is the separation and ...
Counter-Current Leaching of Low-Grade Laterites with …
A hydrochloric acid hydrometallurgical process was evaluated for Ni and Co extraction from a low-grade saprolitic laterite. The main characteristics of the …
Hydrochloric acid regeneration in hydrometallurgical processes: a
ABSTRACT. Hydrochloric acid regeneration has become a vital stage in most chloride process flowsheets. Pyrohydrolysis has been the traditional method of regenerating hydrochloric acid from a variety of chloride solutions, including magnesium, iron and nickel brines, however, its high thermal requirements renders it uneconomic in …
Kinetics and mechanism of hydrochloric acid leaching of rare …
Recovery of rare earth elements (REEs) from tailings is the solution to the waste of valuable resource and hazard of tailing dam. In order to lower the cost and …
What Controls the Leaching of Magnesite with Concentrated …
ABSTRACT. The kinetics of the leaching of natural magnesite with hydrochloric or nitric acid has been studied. Relatively high values of the apparent activation energy (from 46.5 to 70.0 kJ mol −1), but especially the low values of the apparent reaction order for H + cations, n, have shown that the whole process is …
Hydrometallurgical processing of magnesium minerals – …
Hydrochloric acid is another media used in magnesium extraction tests, as in the case of Özdemir et al. (2009) who leached previously dried magnesite tailings with hydrochloric acid, with particle sizes ranging from 750 down to 37.5 μm, an acid concentration between 0.1 and 2 M, a reaction temperature of 10 to 40 °C, a solid-liquid …
A hydrochloric acid process for nickeliferous laterites
3.1. Chloride based processes – literature survey. Hubler and Archibald (1938) patented a process for leaching high Mg % ore in cold 4 to 20% HCl continuing leaching to acidity <1% to give selectivity for Ni over Fe. Pawel (1952) employed a similar route using a ceramic-lined reactor with hydroxide precipitation of the metals by MgO …
Iron Control in Atmospheric Acid Laterite …
Iron control in the atmospheric acid leaching (AL) of nickel laterite was evaluated in this study. The aim was to decrease acid consumption and iron dissolution by iron precipitation during nickel …
Atmospheric acid leaching of nickel laterites review. Part II. Chloride
The sulfation-roasting-leaching process has the potential to change this scenario once it can be applied to all kinds of nickel laterite ores and does not consume much acid, as in the atmospheric ...
High pressure acid leaching of a refractory lateritic nickel ore
Highlights Leaching temperature, leaching duration, sulfuric acid to ore weight ratio and particle size of the limonitic nickel laterite ore were studied. Optimum parameters determined as 255 o C, 0.30 sulfuric acid to ore weight ratio, a particle size of −850μ, 1 h of leaching duration with 30% w/w. 87.3% of Ni and 88.8% of Co in …
Selective Copper Recovery by Acid Leaching from …
95% copper from the leach liquor [12]. Another leaching process used a spent acid etching solution with the assistance of ultrasound at 300 W and further adjustment of pH by lime to 2.5, obtaining a high Cu leaching efficiency of 93.76% and a noticeably low Fe extraction of 2.07% [9]. Sulfuric leaching
Recent Progress in Hydrometallurgical Processing of Nickel …
This section describes the following leaching processes: AL, HPAL, DNi, NPAL, the Caron process (carbonic acid leaching), phosphoric acid leaching, and …
(PDF) Atmospheric acid leaching of nickel laterites review …
Lower CAPEX b, d, e, g, h Higher acid consumption (to obtain acceptable nickel recoveries) c, e, f, h Residue more voluminous (from tank leaching) b, h More magnesium in the waste liquor compared to limonite HPAL c, d, e, h May consume more limestone c, h No significant improvement in OPEX (depending upon how second generation HPAL plants ...
Refining of Gold- and Silver-Bearing Doré
The most viable alternative to aqua regia, however, is the use of chlorine gas in combination with hydrochloric acid. In this process, chlorine gas is bubbled through a vigorously agitated suspension of atomized gold powder and hydrochloric acid. Gold dissolution occurs by the following reaction: (34.15) 2 Au + 2 HCl + 3 Cl 2 → 2 HAuCl 4
ANDRITZ METALS SPRAY-ROAST ACID REGENERATION …
currently focusing on a nickel ore leaching process, which requires both a feasible iron control and acid regeneration step. In addition, we disclose the results of a magnesium ore and aluminium ...
Kinetics and mechanism of hydrochloric acid leaching of …
Recovery of rare earth elements (REEs) from tailings is the solution to the waste of valuable resource and hazard of tailing dam. In order to lower the cost and increase the rate of REEs recovery, we investigated leaching kinetics and dissolution mechanisms of REE slag in hydrochloric acid (HCl) solution, and present a method for …
Efficient Separation and Recovery of Vanadium(V) from Hydrochloric Acid …
Hydrochloric acid leaching has been widely used in the recovery process of vanadium due to its efficient selectivity. It was necessary to further separate vanadium from hydrochloric acid leaching solution. Four extractants of P204, P507, Cyanex272, and N1923 were compared for extraction of vanadium from a simulated hydrochloric …
(PDF) Engineering aspects of the selective acid leaching process …
The AMAX Acid Leach Process for oxide nickel ores generates leach liquors that can vary considerably in their nickel, cobalt, iron, aluminum, manganese, and magnesium concentrations.
Decomposition of mixed rare earth concentrate by NaOH …
The rare earth leaching process in the roasted ore is divided into the following six steps. 40, 41, 42 The main influencing factors of the kinetic process of hydrochloric acid leaching roasting ore are the initial HCl concentration and the reaction temperature: 1. H + is transported from the leaching solution to the surface of the solid ...
Hydrochloric acid regeneration in hydrometallurgical …
Hydrochloric acid regeneration has become a vital stage in most chloride process flowsheets. Pyrohydrolysis has been the traditional method of regenerating hydrochloric acid from a variety of chloride solutions, including magnesium, iron and …
Kinetics of Hydrochloric Acid Leaching of Copper from its …
The effects of some experimental parameters on the copper leaching process were investigated and presented in a previous article, while in the current article kinetic models to represent the ...
Extraction of magnesium from calcined dolomite …
Magnesium is widely used in varieties industrial sector. Dolomite is one source of magnesium besides seawater. The extraction of magnesium from dolomite ores can be done by leaching process.
The Austpac ERMS and EARS Processes for the Manufacture …
A new process of "mechanical activation–hydrochloric acid leaching–concentrated sulfuric acid decomposition–water leaching–separation of Fe3+ with EDTA during hydrolysis" was proposed ...
Advances in Gold and Silver Processing
and 2 g/L respectively while the hydrochloric acid level varied. In a 0.5 % hydrochloric acid solution, 28 % of the gold was extracted in one hour. Gold extraction increased to 33 % in a 1 % HCl solution and to 60 % in a 2 % HCI solution in the same 1 hour span. Hiskey and Atluri (1988) reviewed an Eh-pH diagram for the Au-Cl-H20 system, which
Hydrochloric acid regeneration in hydrometallurgical …
Hydrochloric acid (HCl) leaching is widely used in the mineral processing industry due to its advantages in terms of leaching efficiency, and operation condition …
A closed-circuit cycle process for recovery of carbon and …
The second is that 0.44 mol/L hydrochloric acid (calculated from the data in Table S1) was sufficient to dissolve the impurities contained in 3 g SCC, so 0.5 mol/L hydrochloric acid is enough to leach most of the impurities in SCC. With the increase of acid concentration, the carbon content of SCC-HCl increases continuously.