Dust in Mineral Processing

The generation of airborne dust is a significant problem for the mineral industry. Previous studies in the literat-ure concluded that surfactants were the most effective dust suppressant agents since they enhance the wetting characteristics of the material. However, personnel in the iron ore industry have reported that these agents were not effective. Why is it that surfactants are effective for materials like coal but not iron ore? If surfactants can not control dust levels, what other reagents should be considered

Process for the extracting oxygen and iron from iron oxide-containing ores

Oxygen and metallic iron are produced from an iron oxide-containing mineral, such as ilmenite, by extracting iron from the mineral with hydrochloric acid, separating solid residue from the resulting solution and drying same, electrolyzing the separated, iron chloride- containing solution to produce electrolytic iron and chlorine gas, combining the chlorine gas with water recovered from the drying and/or iron chloride-containing solution electrolysis steps of regenerate hydrochloric acid and recycling the hydrochloric acid to the extraction step. In an alternate embodiment, the chlorine gas is reacted with recovered water in the presence of a catalyst to produce hydrochloric acid which is recycled to the extraction step, thereby eliminating the need for water electrolysis and a separate hydrochloric acid regeneration step. In another alternate embodiment, electrolysis of the iron chloride-containing solution is operated to produce oxygen instead of chlorine gas at the anode and hydrochloric acid is generated concurrently with plating of iron at the cathode. This hydrochloric acid is recycled to the extraction step, thereby eliminating the need for water electrolysis and a separate hydrochloric acid regeneration step.https://digitalcommons.mtu.edu/patents/1089/thumbnail.jp

Method for producing powder from polycrystalline inorganic material

A method for producing powder from polycrystalline inorganic material by contacting polycrystalline inorganic material with the vapor of one or more reduced alkali metals in an environment substantially free of oxygen for a period of time sufficient to cause disintegration of the polycrystalline inorganic material into powder. The polycrystalline inorganic material may consist of one or more oxides, sulfides, or silicates, or combinations thereof. The poly crystalline inorganic material may also comprise a rock or mineral, such as basalt or pyrite.https://digitalcommons.mtu.edu/patents/1070/thumbnail.jp

Flotation column with adjustable supported baffles

An apparatus for separating by froth flotation hydro- phobic and hydrophilic particles contained in an aqueous slurry, the apparatus comprising a generally vertical tubular column having an upper froth zone, an upper separation zone, a lower separation zone, an air inlet zone, and an intermediate feed inlet zone; a feed inlet, air inlet, froth outlet and a tailings outlet; an upper baffle unit comprising a plurality of horizontally extending upper baffle plates, a vertical upper support member including an upper end portion, and first upper apparatus for removably mounting the upper baffle plates on the upper support member at predetermined vertically spaced positions; each of the upper baffle plates comprising a mounting aperture and a plurality of flow apertures; and a second upper apparatus for removably supporting the upper support member in the column with the upper baffle plates in the upper separation zone. The apparatus can include a lower baffle unit. The open area of each baffle plate and the vertical space between adjacent baffle plates can vary between different baffle plates in dependence upon the position of a baffle plate in the column, or in dependence upon one or more of the following: a solids flow rate at the position, a liquid flow rate at the position, and a gas flow rate at the position. The invention also provides a method for improving the operating performance of an unbaffled column.https://digitalcommons.mtu.edu/patents/1076/thumbnail.jp

On-line analysis of ash containing slurries

The ash content of coal suspended in a slurry is determined by bombarding a sample of the slurry flowing past a window of a measuring chamber with radiation from an annular nucleonic source, such as Cm-244, for emitting radiation within the range of about 7 to about 30 KeV and causing the sample to emit both backscat- tered and iron fluorescent x-rays. These x-rays are detected by a radiation detector which produces first and second electrical signals representative of the intensity of each. The density of the sample flowing from the measuring chamber is measured, such as by a nucelonic density gauge, to produce an electrical signal representative of the density and the ash content is determined from the detected intensities of the backscattered and iron fluorescent x-rays and the sample density.https://digitalcommons.mtu.edu/patents/1093/thumbnail.jp

Is the fish-hook effect in hydrocyclones a real phenomenon?

Although the fish-hook effect has been reported by many for a very long time, scientists and practitioners alike share contradictory opinions about this phenomenon. While some believe that it is of physical origin, others opine that it is the result of measurement errors. This article investigates the possibility that the fish-hook effect could indeed be measurement error related. Since all the experimental errors are embedded in the raw size distribution measurements, the paper first lays down the steps that lead to estimation of the partition function and confidence bounds, which are seldom reported in hydrocyclone literature, from the errors associated with the experimental size distribution measurements. Using several data sets generated using a 100 mm diameter hydrocyclone operating under controlled dilute to dense regimes, careful analysis of the partition functions following the developed methodology yields unambiguous evidence that the fish-hook effect is a real physical phenomenon. An attempt is also made to reunite some of the major contradictory views behind the existence of the fish-hook based on sound statistical arguments

Novel Binders and Methods for Agglomeration of Ore

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. A primary example of this is copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process. As a result, operators of acidic heap-leach facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of other agglomeration applications, particularly advanced primary ironmaking

NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not breakdown during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process. As a result, operators of many facilities see large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching

Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control

The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. This will save energy by reducing the amount of material that is ground below the target size, and will also reduce the quantity of materials wasted as slimes that are too fine to be useful. This will be accomplished by: (1) modeling alternative circuit arrangements to determine methods for minimizing overgrinding, and (2) determining whether new technologies, such as high-pressure roll crushing, can be used to alter particle breakage behavior to minimize fines production. In the sixth quarter of this project, work was centered on analyzing the considerable plant data gathered during the first year of the project. Modeling is being carried out of the hydrocyclone portion of the grinding circuit, since this has been identified as the primary source of overgrinding and inefficiency

Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control

The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flow rates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, high-density particles in the circuit until they are overground, and improving existing models to accurately account for this behavior; and (3) Evaluation of advanced technologies to improve comminution efficiency and produce sharper product size distributions with less overgrinding