Blogs
XRF for Better Plant Metallurgy Control
An un-monitored (un-assayed) tailing from a vibrating screen was exiting the system. Operators would eyeball the Zinc content from a handcut while true assays were only provided late the next day as part of the metallurgical material balance. Here I show 4 videos of the new step by step solution we implemented. It used a pizza oven as a drier, a
Preparing Flotation Reagents
The following flotation reagent mixing system is typical for the flotation reagent mixing systems: A-208, Xanthate and Sodium Silicate. The reagent mix tanks, for the above mentioned reagents, are located on the basement floor. Feed chutes from the main operating floor carry dry or wet reagents to each mix tank. Either reclaim or fresh water is added to the mix tank
Flocculant Mixing Strength
Table of ContentsMeasuring Flocculant StrengthEffect of agitation intensityEffect of flocculant dosage A Flocculant like the Dry polymer (Percol 156) is used throughout the process to flocculate fine particles and increase the solids settling, filtration and clarification rates. Flocculant is prepared and aged in the skid mounted automatic flocculant mixing system. A control panel for the system is mounted on the same
Lime Addition System
The lime system is a packaged unit which operates automatically and continuously. The equipment provided in the package includes the lime silo, rotary feeder, lime slaker and lime slurry mix tank and agitator. The lime system is equipped with its own PLC which automatically provides lime slurry for the process. Hydrated lime is stored in a 250 tonne lime storage silo. The
Effect of Operating Variables on Metallurgical Process Parameters
VARIABLE RANGE EFFECT ON PROCESS Crushing Jaw Crusher Close side setting 3″ plus H – Material too large for cone crusher. N – 3″ L – Reduction in capacity. Excess power draw. Cone Crusher Close side setting 3/8″ – 1″ H – Increased circulating load of screen and cone. N – 1/2″ L – Increased power consumption, decrease capacity. Dust Collector recirculating % solids
Gold and Silver Refining
In our EXAMPLE precipitate from the – Zinc Precipitation Circuit will be considerably wet and therefore it must be dried prior to entering the induction furnace. Excess moisture in the precipitate essentially wastes energy; as energy is required to evaporate the water before the precious metals and fluxes are melted. In addition, water not only wastes energy but it may cause small
Merrill-Crowe Zinc Precipitation Startup and Shutdown Procedure
The Operation of a Merrill-Crowe Zinc Precipitation circuit requires for Preparation for its Startup that the following items be checked before the equipment in the Merrill-Crowe Zinc Precipitation Circuit is started. Note the levels in the pregnant solution, clarified solution and barren solution tanks. The pregnant and barren solution tanks should be approximately half full. If the pregnant solution tank is full and the barren solution tank
Gold & Silver Merrill-Crowe Zinc Precipitation Circuit Operation
In the Merrill-Crowe Zinc Precipitation, the pregnant solution tank collects the gold and silver bearing solution recovered from other circuits of the plant: thickener overflow; primary and secondary filtration? and the Argentite circuits. Normally these solutions contain very little solids content (15-100 ppm), however, even this small amount of solids is sufficient to inhibit efficient gold and silver recovery. The
Silver Sulphide Leaching & Filtration Circuit Startup & Shutdown Procedures
Details of good silver sulphide leaching and filtration circuit operation and instructions for sequencing and preparing for startup. The following items must be checked before the equipment in this EXAMPLE Argentite Leaching Circuit is started. The leach tank agitators should be running. Check that the Argentite filter feed pump, drum filter, repulper and tailings sampling pump are available to start up.
Silver Flotation Concentrate Leaching and Filtration Circuits
Producing a Silver Flotation concentrate from this EXAMPLE Argentite (cubic silver sulfide (Ag2S)) Flotation Circuit enters the first of four successive Argentite leach tanks. The purpose of this leach circuit is to dissolve the silver and gold recovered in the Flotation Circuit. A high strength solution of sodium cyanide, air, and lime are added to the first tank to provide the
Flotation Circuit Startup and Shutdown Procedure
In preparation for this EXAMPLE Startup, the following items must be checked before the associated conditioning and flotation equipment and circuit is started. Ensure that all applicable reagent systems are operational, and that the conditioning tank agitators, flotation feed pumps, flotation mechanisms, flotation blower, and the rougher concentrate, cleaner tails, and argentite leach feed pumps are operational. The samplers should have plant air, and should
Silver Mineral Argentite Flotation Circuit
Solid residue from the second filtration stage is repulped with reclaim water to 35% solids, and is pumped to our EXAMPLE Conditioning and Argentite Flotation Circuit which is a process for the recovery of this Silver Mineral. A large portion of the silver in the ore will not have been leached in the initial grinding and leaching circuits. It is therefore
Filtration Circuit Startup & Shutdown Procedure -Merrill Crowe
In Preparation for Startup, the following items must be checked before the equipment in the filtration circuit is started. Check that the filters, repulpers, filtrate pumps, vacuum pumps, flotation blower, and transfer pumps are ready to run. Check that the cooling water compressant system is functional. The selected cooling water filter must be clean, and reclaim water must be flowing through the heat
Merrill Crowe Slurry Filtration Circuit Post-Agitated Leach
The object of the post agitated leach drum filtration circuit is to recover as much of the dissolved gold and silver as possible. The efficiency of recovery can be increased significantly by utilizing two successive stages of filtration such as the two stage system applied in this plant. Recovery of the precious metals is also improved by the use of spray
Agitated Leaching Circuit Operation -Startup -Shutdown Procedure
Ground slurry from the trash screen enters this EXAMPLE Agitated Leach circuit at a rate of 35.5 cubic meters per hour, and 45% solids. The slurry passes through each of the four tanks, and should remain in each tank for a period of approximately 12 hours. Each tank is 8 meters in diameter by 8.5 meters high, and is designed
Dissolve Gold and Silver with Cyanide
The addition of gold or silver to an alkaline sodium cyanide solution will cause the gold and silver to react with the cyanide and dissolve into the solution in a process called cyanidation. This process is more frequently referred to as leaching. As well as reacting with the precious metals, the cyanide will react with iron, copper or zinc that
Thickener Startup & Shutdown Procedure
An EXAMPLE Startup of the thickener may occur under two sets of very different circumstances: After a major plant shutdown or the initial plant start-up, when the thickener is completely empty OR/AND After a shutdown whereby the thickener has been left full of pulp, and rakes and underflow pumps have been inoperative (such as after a power failure). In the
Mill Feed Thickener Operating Principles
Under normal conditions our EXAMPLE mill feed thickener rake drive will operate with the gear mechanism lowered, regardless of grinding or leaching operations. Operating lights on the mill control panel indicate whether the rakes are fully lifted, fully lowered, moving up or down, turning or stopped. An exact intermediate rake position is not indicated on the panel; however, close scrutiny
Ball Mill Operation -Grinding Circuit Startup & Shutdown Procedure
Ball Mill and Grinding Circuit Preparation for Start-UP The following items must be checked before the equipment in the Grinding Circuit is started. Check the ore slot feeder for obstruction or hang—ups. Check the ball mill belt feeder for undue buildup of material. Check oil level in ball mill lube oil tanks. Also, check grease level in the mill ring gear
Grinding and Classification Circuit
Our EXAMPLE Grinding and Classification Circuit is designed to grind 500 tonnes of ore per day, operating 24 hours per day, with an availability of 95%. This circuit will grind -5/8″ material from the Crushing Plant, classify the slurry in one of two cyclones, and pass 70% of the minus 200 mesh material to the mill feed Thickener Circuit at
Calculating DWi from Axb Drop Weight Test Results
Table of ContentsMethodA different equationData filteringResultHardness Data Table 1DWi The drop weight test is a common laboratory measurement used to determine the comminution characteristics of rock samples. A common metric derived from a drop weight test is a value “A×b”. Another common metric that is derived from the SMC Test™ variant of a drop weight test is a “Drop Weight
Why Oxygen is Important in Cyanidation
The Rule and Function of Oxygen in Cyanidation.—Oxygen appears to be an indispensable factor, either directly or indirectly, in the dissolution of gold and silver by cyanide solutions, except in the case of the haloid compounds of silver. Whether the action of oxygen in the dissolution of gold be a direct one, as illustrated by the Eisner equation, or an indirect
200 TPD Crushing and Grinding Circuit Feeding Gold Leaching Plant
I was asked to “size/design” the crushing and grinding circuit required to process 200 TPD of a mystery ore = without hardness or much sizing data. All I had were a set of videos showing how the current 50 TPD plant worked at feeding the gold leaching carbon adsorption plant. I had to improvise a bit. The current “a la