Blogs
How to Size a Thickener
Knowing how to size a thickener and determine the capacity required to handle a pre-determined tonnage of a certain pulp, by overflowing a clear solution and obtaining the desired pulp density of thickener discharge, depends upon the settling rate of that particular pulp. The settling rate of any pulp is easily determined by simple laboratory tests such as outlined below: Laboratory
Rittinger and Kick’s Laws of Crushing
I happen to be one of those who believe that Rittinger probably meant what he said when he wrote what Stadler has quoted, “the increase of the surfaces exposed is directly proportional to the force required for reducing” “and therefore also to the work absorbed in effecting the separations.” (The italics are now mine instead of Rittinger’s or Stadler’s.) Our
Flotation using Acid
The mineral that is two millimetres and under in size is sent to the Hardinge mills for re-grinding. These mills are 10 ft. diam. by 4 ft. long, and are in closed circuit with simplex Dorr classifiers, one classifier to each mill, 6 mills to the section, and 8 sections in the establishment. The overflow from the classifiers goes to
Pulp Formulas & Metallurgical Formulas
Table of ContentsCollected Formulas Metallurgical Formulas Definitions. “Pulp,” in flotation terminology, is a freely-flowing mixture of powdered ore and water. “Pulp density,” when the phrase is applied properly, indicates the specific gravity of the pulp. “Percentage of solids” means the ratio, expressed as a percentage, of the weight of the solids in a pulp to the total weight of pulp. “Pulp consistency” is the ratio,
Gold and Silver Metallurgy Technology
An ore may be treated experimentally with cyanide solution and 90 per cent, of the gold or silver dissolved. This may be quoted as an extraction of 90 per cent., but it is preferable not to do so, since it is, at best, only an experimental extraction; and by no parallel method of operation in practice could such an “extraction”
Diagonal Plane Shaking Table Design
Recent experiments indicate that the usual type of gold concentrating-table is not only poorly adapted to produce the desired results, but also is based upon an incorrect principle, namely, the use of riffles to perform the work of stratifying the various minerals. We have heard a good deal about riffles for concentrating-tables; exhaustive experiments have been made to discover the proper
Crushing Energy & Work of Crushing Machines
A general awakening of interest among mill men concerning the mechanical efficiencies of their crushing machines is evident from a perusal of the recent files of mining publications. Considering the large part of the power bill which must be debited to the crushing department, such interest is natural. When, however, the articles on the subject are read, the only statement upon
Ammonia-Carbon Dioxide Ore Treatment
Most metallurgists appreciate the great need of a process for the extraction and recovery of valuable metals from complex ore, where the presence of one metal increases the cost of extracting the other metals to such an extent that not any of the metals can be extracted at a profit. We need only refer to some of the mines in Colorado,
Fine Grinding in Cyanide Plant
This plant, near Marysville, Montana, was planned to treat the ore from the Piegan and Gloster mines, the latter being one of the early and famous producers of the Marysville district. When the mill was closed, treatment consisted of stamp milling, followed by pans and settlers for pan amalgamation. The extraction was evidently poor, because, a few years later, thousands of
Flotation Controlling Factors
The object of this paper is to offer some suggestions to assist metallurgists to supervise the operations of flotation plants. We do not yet thoroughly understand what “flotation” is, or “why minerals float,” and all attempts that have been made to explain the phenomena have been based on theory or imagination, and have not been capable of substantiation by practical demonstration,
Conical Mill Grinding Tests
In the laboratory work described in the following pages, a 4 ½-ft. Hardinge mill with three removable cylindrical sections, 16 in. each in length, was used. Fig. 1 shows the mill with three cylindrical rings in place. This combination allows a mill 4 ½ ft. by 0 in., 4 ½ ft. by 16 in., 4 ½ ft. by 32 in., or 4
Calculate a Settling Tank’s Capacity – Thickener
Table of ContentsThickener DesignPractical Principles:Tests For Determining Settling Equipment:Scope of Laboratory Tests:Effects of Lime:Effects of Temperature:Settling Problems at El Tigre: During construction work at a mill, the metallurgical engineer in charge, ran a series of experiments on settling. His tests proved that deep settling tanks were not ordinarily necessary. The use of tanks 2 or 3 ft. in depth was suggested. Later
Measuring Settling Rates and Calculating Thickener Capacity
Table of ContentsThickener DesignThe Four Settling ZonesSlimes Classified as to Settling RateType 1 of SettlingType II of SettlingFormula for Determining Capacity of Continuous ThickenersThickening in Zone D and Consistency of Discharge PossibleSummary of Slime-Settling ResultsTo Ascertain the Necessary Depth of TankMethod of Making Settling TestsSpecial Apparatus for Small-Scale Continuous Settling TestsRemarks Concerning Settling Tests In order to develop rational methods of measurement
List Books on Cyanidation
ALLAN, A. W.: Mill and Cyanide Handbook, Charles Griffin & Company Ltd., London, 1918. ALLEN, ROBERT: West Australian Metallurgical Practice, Chamber of Mines of Western Australia, 1906. BAIN, H. F.: More Recent Cyanide Practice, Mining and Scientific Press, San Francisco, 1910. BERTELSMANN, WILHELM: Der Technologie der Cyanverbindugen, Munchen and Berlin. 1906. BOSQUI, F. L.: Practical Notes on the Cyanide Process,
Gold Room Security
Table of ContentsGold Bullion Room RecordsMinimum Security Standards ChecklistMetallurgical AccountingGold Room Operations Gold Room Security Other Goldroom DutiesMore SecuritySafetyReagents and FluxesHand Safety and HandlingGeneral Safety Very little is documented about Gold Room Security due to the sensitivity of people around it. At the same time, when establishing a new operation it is useful to have a standard security starting point on which to address
Factors Controlling the Capacity of Rock Crushers
When estimating the capacity of crushers under given conditions, it is necessary to employ an empirical factor which has here been designated by the letter k, representing the percentage ratio between actual crushing rate, and a theoretical capacity based on the dimensions and other data correlated in equation (12). The accuracy of this factor limits the precision of the estimate.
Open or Closed Circuit Crushing
Table of ContentsClosed Circuit Reduction-Stage CapacitiesCrusher’ Screen Efficiency FactorHow Much Circulating LoadClosed Circuit Crushing Calculations The factors governing the determination of capacity for any open circuit crushing stage are much the same as those we outlined in connection with the secondary stage. In a properly designed crushing plant, excepting those plants which by-pass a portion of the pit-run around the
Geometallurgy
Table of ContentsSamplingOre Grade and Final ProductMetallurgical ProcessPlanningProduction PlanGeometallurgy Course The variability in gold recovery (geometallurgy) is a very important problem to study during the first steps of the project and even during the operation. Probably, the explanation of that problem for some plants is not well known and the problem has to be solved with valid criterion that were
List Gold Metallurgical Tests
In order to have a preliminary idea about the metallurgical performance of the samples, some scoping tests have to be performed. They can be carried out in the prospective mine site and/or special metallurgical laboratory. The final election is based on the equipment availability and gold mineralization. Test to be done include; concentration by gravity, flotation and leaching. Rotary Sampler
Crushing Plant: Surge Bins VS Stockpiles
I need to further comment on the influence of surge storage upon plant operation. The provision of adequate surge storage at the right places in the flow line is of sufficient importance to warrant a little further consideration. It is desirable, in the crushing plant, as it is in any production process, to achieve a smooth and uninterrupted flow through the
Process Mineralogy
Table of ContentsGold Metallurgy PerformanceMineralogical Studies The treatment of auriferous ores presents several challenges to the metallurgists and plant operators due to there are some factors that have an important impact on the process. Without any doubt the mineralogy is the key aspect of the process performance. Basically, there are several options to be considered at the moment of evaluate
Gold Extraction & Recovery Processes
Table of ContentsProcess DevelopmentSelecting a ProcessGold RecoveryAmalgamationFlotationLeachingCyanidation Process Development Considering the different gold minerals present alone or combined with the host rock, it will be necessary to discharge the unwanted material in order to increase the concentration of gold in an economically manner. This part treats the strategy of beneficiation as a combination of several processes. Joining together these units
Auriferous Deposits
Table of ContentsGold OccurrenceGold Sources Gold and elements of the platinum group metals have been found in several types of deposits around the world. Sometimes, deposits have been worked for their cobble and gravel components and these places have been set up to recover heavy minerals (mainly as black sands) from their host rock. These minerals carry precious metals and