Surface kinetics and pressure dependence of propane oxidation …
The catalytic total oxidation of propane over platinum was investigated experimentally and numerically at pressures of 1–7 bar and catalyst temperatures up to 700 K.
Scaleup of pressure oxidation processes | Mining, …
The successful commercialization of a pressure oxidation (POX) process for recovering metal values, including gold, copper, zinc, nickel and molybdenum, is the result of a carefully planned development program. The initial task involves developing one or more conceptual flowsheets, including the POX autoclave and downstream purification and recovery …
Pressure Oxidation Modelling for Design and Optimisation
Pressure oxidation has become a widely accepted technology for treating refractory gold ores. When sizing autoclaves for pressure oxidation, several major factors must be considered, including ...
Pressure Oxidation of Molybdenum Concentrates
Pressure oxidation offers an alternative to a pyrometallurgical circuit by extracting molybdenum and rhenium from the concentrate without penalization due to the presence of copper. This study ...
High-pressure oxidation of hydrogen diluted in N
The oxidation of H 2 diluted in N 2 with and without 10 % H 2 O or 20 % CO 2 additions are studied at fuel-lean conditions at 100 atm and 500–1000 K in a supercritical-pressure jet-stirred reactor. The mole fractions of H 2 and O 2 are quantified by using micro-gas chromatography (µ-GC). Experiment shows that H 2 oxidation is inhibited at lower temperatures (850–950 K) …
Titanium: A Solution for Highly Corrosive Hydrometallurgical
They can range from atmospheric heap leach operations to more sophisticated pressure acid leaching processes (PAL) and pressure oxidation leaching processes (POX). Titanium is the metal of choice ...
Under Pressure and Feeling the Heat: Autoclave …
Pressure Oxidation (POX) POX is a process that can be used in the extraction of various metals, including gold, copper, zinc, and nickel from both ore and from various sulphide intermediates.
Complete process and equipment solutions for …
A typical pressure oxidization (POX) circuit for refractory ores consists of the following main process steps: comminution and flotation followed by carbonate removal, chloride removal, pressure oxidation, vent-gas …
Gold Sulphide Ore Oxidation by Alkaline Pressure
Alkaline pressure oxidation using NaOH and oxygen, first proposed by Sill (1960), was used commercially for treating a cobalt-nickel arsenic ore (Chilton, 1958). Alkaline pressure oxidation is currently being used at the Barrick Mercur Gold Mine, Utah. The operating conditions at Mercur are 220° c and up to 460 psig pressure and pH between 7 ...
GOLD PRESSURE OXIDATION CIRCUIT DESIGN: A 40 YEAR …
This paper presents a historical review of high temperature pressure oxidation operations and current projects in execution with a focus on the autoclave vessel design, …
High Pressure Oxidation of Silicon in Dry Oxygen
The effects of oxidant pressure on the kinetics of thermal oxidation of (100) and (111) oriented silicon wafers in dry ambients were investigated over the temperature range of 800°–1000°C and the pressure range of 1–20 atm. The parabolic and linear rate constants were found to be proportional to oxygen pressure to the power of 1 and 0.7, respectively.
High pressure oxidation of NH3/n-heptane mixtures
Previous experiments for ignition and oxidation of NH 3 / n-heptane fuel mixtures were conducted at pressures well below those of engines and gas turbines.In the present work, experiments are conducted at pressures up to 100 atm in the DTU laminar flow reactor and the Princeton supercritical pressure jet-stirred reactor to characterize the high-pressure features …
In-situ electrochemical study on the effects of Fe(III) on …
In this paper, in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment. The results illustrated …
High-pressure oxidation of methane
Methane oxidation at high pressures and intermediate temperatures was investigated in a laminar flow reactor and in a rapid compression machine (RCM). The flow …
Experimental and kinetic study of ammonia oxidation and …
The reaction sequence of the H 2 NO system during the high-pressure oxidation of ammonia, where blue is the consumable, red is the product, and green is the chain carrier. 4.3. Effects of elevated pressure on NO x formation. As shown in Section 4.2, pressure has a significant effect on NO x generation at intermediate temperature ranges [40].
Pressure Oxidation Modelling for Design and Optimisation
Pressure oxidation (POX) is a well-established method for processing sulphide material containing refractory precious and base metals [1]. POX typically takes place in a horizontal multi-compartment agitated pressure vessel at a temperature of 150–230 °C …
CASE STUDY REVIEW OF THE ALBION PROCESS AS AN …
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High Pressure Oxidation of Niobium
The oxidation rate is extremely pressure sensitive above 550°C. Theoretical considerations indicate that an equilibrium adsorption process occurs prior to the rate‐determining step. It was necessary to include a term in the rate equation for the interaction between the adsorbed molecules to interpret results above 650°C. The interaction ...
High-pressure oxidation of propane
Propane oxidation at high pressure (100 bar) and intermediate temperature (500–900 K) has been investigated in a flow reactor as a function of stoichiometry. These data extend the propane oxidation benchmark at high pressures and intermediate temperatures. The onset of fuel oxidation was found to be 625–725 K, increasing with fuel-air ...
POX Hub
The Pressure Oxidation facility ('POX Hub') is a cornerstone of Petropavlovsk's strategy and the principal driver of future value for the Company. The ability to process previously untreatable refractory ores, where gold is locked in sulphides, has opened a swathe of new opportunities for the Group to exploit both in the short and long ...
High Pressure Acid Leach
Overview. High Pressure Acid Leach (HPAL) is a process used to extract nickel and cobalt from laterite ore bodies. The HPAL process utilizes elevated temperatures (roughly 255 degrees Celsius), elevated pressures (roughly 50 bar or 725 psi), and sulfuric acid to separate nickel and cobalt from the laterite ore.
High Pressure Metallurgy | Autoclave Technology
Pressure Oxidation (POX) Pressure Oxidative Leach (POL) High Pressure Acid Leach (HPAL) HCl Pressure Leach; Hatch has been at the forefront of implementation of pressure hydrometallurgical processes for over 25 years and is the technology provider of choice for many resource companies. To select the correct process, capital costs, operating ...
Pressure oxidation, gold
Pressure oxidation, gold A list of the mines where different processing of gold ores is carried out is shown in Table 5.12. Although the pressure oxidation process appears to be the current leading technology, selection of the optimum route depends on several factors. Bruckard, W. J. Sparrow, G. J. Woodcock, J. T. Gold and silver extraction from Hellyer lead-zinc flotation …
Leaching and Kinetic Study on Pressure Oxidation of …
The leaching of copper from chalcopyrite in H2SO4 solution under pressure-oxidative conditions and its kinetics were investigated in this study. Leaching variables that affect the rate of copper dissolution from chalcopyrite are agitation speed (300–900 rpm), total pressure (0.8–2.0 MPa), temperature (160–180 °C), and sulfuric acid concentration (0.1–2.0 M). …
Pressure Oxidation Modelling for Design and …
Pressure oxidation · Modelling · Design · Optimisation 1 Introduction 1.1 POX Technology Pressure oxidation (POX) is a well-established method for processing sulphide material containing refractory precious and base metals [1].
Deportment of gold in an autoclave pressure oxidation (AC-POX…
A carbonaceous refractory sulphide ore is processed in an autoclave pressure oxidation plant and subsequently subjected to a cyanide leaching. An initial mineralogical study of the feed ore by quantitative dynamic SIMS analysis has shown that 95% of the gold is contained as sub-microscopic gold in pyrite with the remainder contained in primary ...
Refractory Gold Pressure Oxidation Technology at …
The pressure oxidation circuit, based on treating 70 t/d . arsenopyrite-pyrite concentrate in a single autoclave, replaced the roasting circuit in the existing plant. The Pressure Oxidation process provided the following benefits. to the operation: • Eliminated SO2 emissions • Eliminated arsenic xide production
Copler Sulphide Expansion Project
Limestone will be added to the resultant slurry from pressure oxidation in order to precipitate and lock-up iron and arsenic into stable iron arsenate precipitates. The treated slurry will pass through the two-stage counter current decantation (CCD) thickener to wash the gold-bearing solids. The washed slurry will then be pumped to the pre ...
OneMine | Barrick Gold Autoclaving Processes
This paper reviews the various processes successfully in operation to treat refractory gold ores and describes in detail the alkaline pressure oxidation circuit operating at the Barrick Mercur Mine, Utah, U.S.A., on car- bonaceous/sulphide refractory ore and the acidic pressure oxidation circuit operating at the Barrick Goldstrike Mine, near Carlin, Nevada, …
High pressure oxidation of C2H4/NO mixtures
As the high pressure and intermediate temperature C 2 H 4 oxidation has already been discussed in a previous study [1], the present focus is on the C 2 H 4 –NO x interactions at similar conditions. The presence of NO x introduces additional initiation steps for ethylene, with a smaller barrier than the C 2 H 4 + O 2 reaction. A direct reaction between C 2 H 4 and NO 2 …