Large Melting Furnace – City Waste

The most widely applied method for the disposal of waste materials, including sludges, dusts, scales, leachable slags from smelting or melting operations, and residues from the combustion of organic materials including municipal wastes, is to inter the materials in an appropriate landfill. Small quantities of some wastes are encapsulated within Portland cement or sulfur, and then consigned to a landfill. However, landfill disposal of wastes is at best a short-term solution, because landfills are nearing capacity and new landfills are difficult to establish. A promising and technically viable permanent solution to the problem is to melt the waste materials to produce inherently non- polluting amorphous or crystalline mixtures of inorganic oxide products, similar to slags produced by various metal industries. These products may be useful as aggregate for bituminous or Portland cement concrete, for grit blasting, as road building and construction ballast, and in the manufacture of mineral wool instead of landfill disposal.

In 1984, the ASME Research Committee on Industrial and Municipal Waste asked the U.S. Bureau of Mines about the feasibility of melting (vitrifying) ash residues produced by the combustion of municipal wastes. A demonstration melting test of dry

By David| 2018-04-22T03:23:55+00:00 April 21st, 2018|Categories: Smelting - Melting - Refining|Tags: 993|Comments Off

How to Recover Metal from Mine Drainage Water

To recover metals as sulfide concentrates from contaminated waste streams using hydrogen sulfide (H2S) generated by the bacterial digestion of waste organic materials.

The goal of this research is to develop a treatment method for metal mine effluents that will rival the cost and convenience of conventional lime treatment, and that will provide better effluent water quality, result in less expensive sludge disposal, and allow for the selective recovery of metals.

How it works

In this method (fig. 1), indigenous sulfate-reducing bacteria are used to generate H2S gas in an anaerobic bioreactor containing sulfate-rich mine water and inexpensive, degradable organic matter such as food processing wastes or primary sewage sludge. As H2S is formed, it is sparged from the bioreactor by an inert carrier gas to create a gas stream containing about 0.3 pct H2S. When the gas comes in contact with a metal-contaminated mine effluent, the heavy metals precipitate as relatively insoluble sulfides. Elemental sulfur (S°) also may be formed. By adjusting the pH, the composition of the precipitated concentrates of metal sulfide can be manipulated. For example, the pH of mine water containing Cu, Zn, Fe, Al, and Mn

By David| 2018-04-21T10:42:59+00:00 April 21st, 2018|Categories: Environment & Tailings, Recycling|Tags: 993|Comments Off

Recover Neodymium from Permanent Scrap Magnet

Develop hydrometallurgical or pyrometallurgical recycling methods to recover valuable rare-earth compounds from various forms of NdFeB magnet scrap.

The U.S. Bureau of Mines (USBM) has developed technology to treat and recycle a variety of wastes containing valuable and strategic metals. As part of this effort, the USBM developed a process to separate neodymium and other valuable rare earths from iron in NdFeB magnet scrap (fig. 1). Since this scrap typically contains nearly 30 weight percent neodymium and since the demand for neodymium is constantly increasing, cost-effective methods for scrap treatment could have a significant impact on industrial expenditure and materials supply in the expanding area of magnet manufacture.

Approach

A hydrometallurpical, H2SO4 dissolution-precipitation process provided the most effective treatment for separating rare earths from bulk NdFeB magnet scrap (fig. 2). Precipitation of neodymium-alkali sulfate double salt proved advantageous over direct precipitation of fluoride or oxalate products. This double salt is easily converted to a variety of useful rare-earth compounds, which eliminates, many of the materials handling and economic problems inherent with direct precipitation. Following rare-earth precipitation, dissolved iron was removed from the acid leach solution by precipitation as a jarosite.

By David| 2018-04-21T10:41:03+00:00 April 21st, 2018|Categories: Recycling|Tags: 993|Comments Off

How to Make Graphite Flakes from Steel Waste

Develop a technology for producing high-quality flake graphite from the steelmaking waste known as kish.

Approach: Treat the waste kish as an ore and apply mineral processing techniques of physical beneficiation and chemical purification to produce a range of graphite products competitive with the natural mineral.

Graphite is a naturally occurring form of carbon with a unique combination of properties that make it indispensable in a very wide range of industrial and consumer applications. It has high electrical and thermal conductivity and remains stable to extremely high temperature. It has a low coefficient of friction and is nearly impervious to corrosion. The steel industry is dependent on graphite in clay-, magnesia-, and alumina-bonded refractories for crucibles, bricks, facings, and coalings. Electrical uses include graphite brushes in motors and generators, and electrodes in batteries. The transportation industry needs graphite for clutch and brake linings, and all industries depend on graphite in seals, gaskets, lubricants, and coatings. The consumer sees (graphite in composite plastics and in the common pencil.

As with all natural minerals, the availability of graphite is diminishing and costs are rising as quality decreases.

Furthermore, the United States is totally dependent mi

By David| 2018-04-21T10:43:37+00:00 April 21st, 2018|Categories: Recycling|Tags: 993|Comments Off

Primary & Secondary AG Autogenous Grinding

Primary autogenous mill feed is either primary crusher discharge or run of mine ore, containing material on each size of the screen analysis below the largest piece in the feed. It is subject to the large variations in size analysis normally found in primary crusher products or run of mine ore. There can also be variations due to segregation in stock pile or bin storage. In feeding primary rock mills there is usually no attempt to distinguish between media size and ore feed size. Variations in size analysis, shape, crushability and grindability of the feed are unavoidable and cause wide variations in the feed rate to the mill.

Critical size buildup is a term frequently used in connection with autogenous grinding, particularly in connection with primary rock milling. It can be defined as a buildup or accumulation in the mill of ore or rock- too large to be broken by the coarse fraction of the mill feed and too small to be effective grinding media for grinding the fine fraction of the mill feed. In primary rock mills critical

By Jorge| 2018-04-20T11:20:10+00:00 April 20th, 2018|Categories: Grinding|Tags: 25%|Comments Off

How to Measure Grinding Efficiency

The first two Grinding Efficiency Measurement examples are given to show how to calculate Wio and Wioc for single stage ball mills. Figure 1. The first example is a comparison of two parallel mills from a daily operating report. Mill size 5.03m x 6.1m (16.5′ x 20′ with a ID of 16′).

This example shows that Mill 2 is slightly more efficient than Mill 1 even though it has a higher power consumption per tonne. This shows the use of the work index equation taking into account the differences in feed and product sizes. The calculation is only part of the total plant performance study and must be tied into the total plant operation.

The next example covers an in-plant study on the effect of mill speed on mill performance. The two speeds being studied are 68% and 73% of critical speed in 5.03m (16.5′ diameter inside shell 16′ inside liners) ball mills. This study was over a period of four months. Grindability tests were run on monthly composite samples of the feed to each mill. The operating data, test data and

By Jorge| 2018-04-20T10:54:13+00:00 April 20th, 2018|Categories: Grinding|Tags: 25%|Comments Off

Crushing Finer to Reduce Grinding Cost

This new high energy or power rate crushing brings a different perspective to comminution flow sheet selection. Generally, up until the early 1960’s the classical flow sheet for a beneficiation plant was primary crushing followed by two stages of cone crushing in closed or open circuit, making feed for rod mills, followed by ball mills. The rod mill was needed to reduce feed size to the ball mill because crushing plant output was normally coarser than 80% passing 10,000 microns. Such feed causes power inefficiency if fed directly to a, ball iriill. Even though the rod mill could be a relatively inefficient device for both energy and metal consumption, as was evidenced by Bond it still made the overall circuit energy consumption more efficient.

Under the right operating conditions, high power rate crushing can bring mill feed size down to near 80% passing 7,000 microns and finer, which can be handled

crusher plant designed using power rate energy parameters

more efficiently by ball mills. Based on average field observations, the crushers can do this for less than half the energy and between one-tenth and one-twentieth of

By David| 2018-04-19T17:43:36+00:00 April 19th, 2018|Categories: Crushing & Screening|Comments Off

Allis Chalmers Corporation

The Allis-Chalmers Corporation was founded in Milwaukee, Wisconsin, in 1847 as the E. P. Allis Company, which had an initial interest in manufacturing components in the grinding of flour. As such, its roots were started in reducing material size, which is covered by the generic term, comminution.

The Corporation evolved by a series of mergers into one of the world’s first conglomerate companies.

Several key equipment suppliers to the mining and cement industries, in the late 19th century, became part of Allis-Chalmers and provided a broad base to build the modern technology we are using today.

Because this publication is recommending new approaches in solving old problems, it seems fitting to reflect on some past history to gauge the progress of our technological innovation. During this historical review it has been surprising to find features on equipment almost 100 years ago that one tends, from today’s perspective, to think are relatively new. Some such developments had to be abandoned because of inadequate technology. The fact that such features existed at that time speaks volumes for the intelligence and inventive genius of the early crusher engineers. Some significant features

By David| 2018-04-19T15:05:03+00:00 April 19th, 2018|Categories: Crushing & Screening|Comments Off

Mineral Titles Online MTO BC

Using this summary page you can locate Geological Maps from the MTO Online service in British Columbia to acquire Mineral Titles, Mining Claims.

Mineral Title means a claim or lease acquired and maintained under the Mineral Tenure Act and its predecessor Acts (the Mineral Act and the Placer Mining Act) and these are by far the most prevalent form of title to minerals. The only method of acquiring new mineral rights today requires the registration of a cell claim. A claim is an exploration and development tenure, and a recorded holder may convert a claim to a lease in order to carry out production mining. Information on the methods of claim and lease acquisition and maintenance may be viewed on the Mineral Titles Branch website. This guide deals with the rights and responsibilities of the surface owner and the subsurface mineral title holder where this subsurface right is granted by a mineral or placer claim or lease.

MTO British Columbia

bc_mineral_titles_online_ https://www.mtonline.gov.bc.ca/mtov/home.do

Mineral Claim – Work Requirement in BC

$5 per hectare for anniversary years 1 and 2;
$10 per hectare for anniversary years

By David| 2018-04-19T17:13:37+00:00 April 19th, 2018|Categories: Geology|Comments Off

Crushing Simulation

In the context of this paper a simulation model for a size reduction device is an equation or equation set which allows the calculation of the product size distribution from the device for a specified size distribution of feed. The model might be expressed as a simple algebraic expression, as a matrix equation, or as a finite difference formulation. The model proposed here for once-through crushers was originally derived and developed by Austin, et al for the treatment of smooth double roll crushers. The model is based on the assumption that if the particle size range is split into geometric size intervals (i.e. the √2 sieve series) the breakage of each size interval occurs independently of other sizes.

That is, if fi and pi give the weight fraction of material in size interval i in the crusher feed and product, respectively, the relationship between the pi and fi, can be expressed as the transfer parameter equation (3)