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Metallurgist Handbook – Reference Tables & Charts
Metallurgist Handbook – Reference Tables & Charts International atomic weights Absolute Viscosity of water Thermometric Conversions Thermometric Conversions Fahrenheit to Centrigrade Absorption of Gases By Water Table of Pressure Boiling Point of Water at Various Pressures Stages in Decomposition of Pyrites Value of Lime as an Electrolyte Solubility of Lime in Water at Different Temperatures Value of caustic soda as
Gold/Silver Leaching with Sodium Zinc Cyanide
Dissolution of Precious Metals in Sodium Zinc Cyanide: The dissolving effect of sodium zinc cyanide on precious metals has been the subject of much discussion. According to one researcher, pure K2Zn(CN)4 in the presence of oxygen dissolves gold with the formation of gold potassium cyanide and zinc oxide. Another researcher compared the dissolving effects of KCN and K2Zn(CN)4 on gold. He found
Titration of Cyanide Solutions
Table of ContentsCyanide NaCN Titration EquipmentCyanide NaCN Titration Procedure Titration of Cyanide Solutions Containing Dissolved Zinc: Sodium zinc cyanide reacts with silver nitrate to precipitate zinc cyanide: Na2Zn(CN)4 + AgNO3 = Zn(CN)2 + NaAg(CN)2 + NaNO3 In the presence of an alkali, considerably more silver nitrate must be added to sodium zinc cyanide before a precipitate is formed. Many investigators
Zinc Cyanide & Silver Gold Precipitation
Table of ContentsZinc Cyanogen Complexes and ZincatesSolubility of Metallic Zinc in Cyanide SolutionsSolubility of Zinc Minerals in Cyanide Solutions In cyanidation, zinc (the Merrill-Crowe Process) is practically the universal precipitant for precious metals dissolved in cyanide solutions although for specific reasons aluminium and charcoal have been used. During the reactions involved in precipitation, the greater part of the zinc dissolves
Effect of Temperature on Cyanidation and Gold Leaching Kinetic Rates
When heat is applied to a cyanide solution containing metallic gold, two opposing factors affect the rate of dissolution. The increase in temperature would be expected to increase the activity of the solution and thus increase the rate of dissolution of gold. At the same time the amount of oxygen in the solution would decrease because the solubility of gases
Effect of pH Alkalinity on Gold Leaching
The role pH has in affecting gold leaching rates by cyanide and the functions of calcium hydroxide in cyanidation are as follow: 1. For safety and to prevent loss of cyanide by hydrolysis. 2. To prevent loss of cyanide by the action of carbon dioxide in the air. 3. To decompose bicarbonates in mill water before using it in cyanidation.
Effect of Oxygen on the Dissolution of Gold
In discussing the effect of oxygen on the gold dissolution, one can understand the use of oxygen or an oxidizing agent is essential for the dissolution of gold under normal conditions of cyanidation. Such oxidizing agents as sodium peroxide, potassium permanganate, bromine, chlorine have been used with more or less success in the past; but due to the cost of
Effect of Gold Particle Size on Rate of Dissolution
When coarse free gold occurs in ores, the usual practice is to remove it by means of gold traps, jigs, blankets, etc. ahead of cyanidation. Otherwise, these coarse particles might not be completely dissolved in the time available for cyanidation. Another practice which reduces the size of the gold particles going to cyanidation is the grinding and classification of gold
Gold & Silver Dissolution and Cyanide Concentration
Table of ContentsDecomposition of Cyanide SolutionsDissolution of Precious MetalsEffect of Cyanide Concentration on Rate of Gold and Silver DissolutionRelative Rates of Dissolution of Gold, Silver and Their Alloy By far the most important cyanides used in cyanidation are sodium cyanide and calcium cyanide. The latter product is sold in an impure form analyzing close to 50% NaCN equivalent. The former
Antique hydrometer and Humidi Guide
HYDROMETER, Baume Scale—For heavy liquids, without thermometer. Range: 0 to 70° in 1° divisions. Temperature standard, 60° F. Approximately length, 11 inches. HYDROMETER, Baume Scale—For heavy liquids, without thermometer. Range: 0 to 70° in 1° divisions. Temperature standard, 60° F. Approximately length, 16 inches. HYDROMETER, Specific Gravity Scale—For heavy liquids, without thermometer. HUMIDIGUIDE, Hampton, Taylor—A direct reading hygrometer of modern design
Cyanide Leaching Chemistry & Gold Cyanidation
The reactions that take place during the dissolution of gold in cyanide solutions under normal conditions have been fairly definitely established. Most agree that the overall cyanide equation for leaching and cyanidation of gold is as follows: 4 Au + 8 NaCN + O2 + 2 H20 = 4 NaAu(CN)2 + 4 NaOH In a relatively simple system of this
Online Formula & Calculator Disclaimer
Nothing contained in the calculators, equations or other information on this website constitutes advice. Access to the calculators, equations and other information is donated for academic and research purposes only, and must only be used by qualified comminution/process engineers. Comminution/Process engineers considering the calculators, equations and other information must use their own professional judgement, knowledge and expertise when deciding whether
How to Select a Rainwater Catch Basin
You need to know how much water will be draining to your catch basin in order to select the right catch basin for your project. Catch basins are an effective way to collect surface water that is draining to one specific area like a low spot in the yard or below a rain gutter downspout. Surface water flows through the
Laboratory Reagent Bottles
COLOR OR FLAME SCREEN, Merwin—Transparent celluloid screen in three tints of blue, which will absorb the yellow of sodium flame. Directions for distinguishing the various flame colors are furnished with each screen. BOTTLE, Packing—Green glass, narrow mouth, without stoppers. BOTTLE—Flint glass, narrow mouth, round shoulder, without stoppers. BOTTLE—Flint glass, wide mouth, round shoulder, without stoppers. BOTTLE, Pomade—Flint glass, extra wide mouth,
Laboratory Air Blowers
BEAKER, Copper—With lip. With flared tcp and flat bottom. Spun from heavy copper sheet. BLOWER, Fan, Electrically Driven-—Small fan blower direct connected to high speed motor. The combination is especially designed for operating low pressure crude oil burners as used with Braun Assay Furnaces. The fan is of special construction to produce volume and pressure for atomizing the oil. The outfit is mounted
Toll Milling in Peru
The Peruvian government estimates that illegal mining accounts for about 20% of gold exports. This mining is done by tens of thousands of artisanal, small-scale miners who use metallurgical processes from centuries ago.
Geology For Dummies
Enter Geology- For Dummies! The goal of this book is to break through the overwhelming array of geology information and provide a quick reference for key concepts in the study of the earth. Geology is the study of the earth. By default this means that geology is a vast, complex, and intricate topic. But “vast, intricate, and complex” does not
Beginner Guide to Gold Prospecting
For those of us with even the slightest inkling of gold prospecting in our blood, we know there is no shortage of information out in the world on how to do it. Regardless of our individual experience on mining for gold, we all face the same conundrum on what to do with all the information and science that we come
Orogenic-Mesothermal-Greenstone Gold Deposits Exploration
How to explore or “go prospecting” for a Orogenic-Mesothermal-Greenstone Gold Deposit is described herein starting with what exploration tool can be used? First is magnetic surveys can be very useful exploration tools, when looking for bends and structures that the potential host Greenstone/Orogenic shear hosted gold deposits and mineralization. Gravity surveys can be very successful in assisting mapping the
IOCG Iron Oxide Copper Gold Ore Deposits
IOCG Iron Oxide Copper Gold Ore Deposits goes with porphyries as they are also loosely associated with a large felsic intrusions and form at moderate depths, unlike the dominantly tertiary porphyries IOCG’s tend to be much older and are generally protoizoic in age from 1.1 to 1.8 billion years ago. There are some younger ones but they are in the
Fluorine F Levels -Penalties and Marketability of Copper Concentrate
F Penalties often start at 300 – 500 ppm which is to say 300 ppm in Japan / Korea and perhaps ~ 500 ppm into China. Penalty scales of US $1- 2/dmt per 100 ppm. Some cases Fluorine (F): US $1.00 per dmt for each 100 ppm over 300 ppm Others F: US $2.00 per dmt for each 100 ppm
Crusher Concave Profiles
When used for primary or coarse secondary crushing service, the type of crusher described is usually fitted with the style of concave shown on the upper left. These are known as “standard” or straight-face concaves, which have been the standard type of liner ever since the gyratory crusher came into popular use. The distinguishing features of this type of crusher concave
Crazy Crusher
Hand Operated Jaw Type Ore Crusher – Grinder That above, looks crazy, but this below IS Totally CRAZY! Figure 66 shows the Taylor Hand Crusher. This consists of two jaws, one of which is stationary and one of which is operated by the hand lever. Both jaws are faced with hard white iron. The movable jaw has horizontal corrugations, so