Mineral Harvesting:

There is a choice of two systems:

  • Choice depends on the ph. and composition of the dust.
  • Binds the smallest particles rather than relying on hygroscopicity or surface tension to  secure a weak agglomeration such as by Bitumen Emulsions, Lignosulphonates, calcium salts, oils or surfactants.
  • Does not film form, such as with nano particle thermoplastic emulsions.
  • Allows water penetration through the bound surface, but the binding itself is water insoluble.
  • Allows penetration of difficult surfaces because both systems are true solutions, not dispersions or emulsions.
  • Both systems may be delivered to distant places as pre-prepared fine powders for dissolution or preparation at destination, to avoid excessive transportation costs.
  • Highly cost effective against other systems.
  • Environment friendly – non-polluting, non-toxic.
  • Suitable for rehabilitation of dumps or discard heaps.
  • The diluted cost per liter at source is less than R! for both systems, or for a 50/50 blend.

Which system to use depends on the condition of the surface, its composition and the
nature of the dust.

mineralharverting 1 mineralharverting 2

Mineral fines recovery

Mineral fines are very often in the form of slimes in discard ponds. When wet they are a paste
Which can neither be dried economically nor can it be processed, because pastes cannot be
compressed.

A polymer is mixed with these fines and it is then chemically granulated. These non-sticky
Granules may be dried as they are, at diameters up to 6 – 10mm or otherwise when still wet, they may be further reduced in size and then subject to compression in any of: briquetting, extruding (when in a jelly-like consistency), or into blocks

 

mineral fines recovery

Rock bolt anchors

  • Conventional rock bolts are anchored by thermosetting resins such as an unsaturated polyester in a plastic
  • capsule which is in two longitudinal halves. One contains the resin with extenders and the other a catalyst,
  • also with extenders. When the bolt is thrust through this capsule and rotates in doing so, the binders are mixed
  • and set. Setting time is variable from 30 seconds or more and a ‘pull resistance’ of up to 20 tons is required to
  • be developed within a specific time. In South African mining up to 200 000 of these bolts are used per day.
  • They are used to stabilize the hanging wall in mining, particularly coal mining, in tunneling and in road cuttings.

 

rockbolt

Dust suppression

 We have a dust suppression that has a number of unique attributes, which are summarized as

follows:

 

  • A choice of two chemical systems, or a blend. Choice depends on the pH and composition of the dust.
  • Binds the smallest particles rather than relying on hygroscopicity or surface tension to secure a weak
  • agglomeration such as by Bitumen Emulsions, Lignosulphonates, calcium salts, oils or surfactants.
  • Does not film form, such as with nano particle thermoplastic emulsions.
  • Allows water penetration through the bound surface, but the binding itself is water insoluble.
  • Allows penetration of difficult surfaces because both systems are true solutions, not dispersions or emulsions.
  • Both systems may be delivered to distant places as pre-prepared fine powders for
  • dissolution or preparation at destination, to avoid excessive transportation costs.
  • Highly cost effective against other systems.
  • Environment friendly – non-polluting, non-toxic.
  • Suitable for rehabilitation of dumps or discard heaps.

 

dust

Spontaneous combustion

 

  • This relates to “hot spots” or explosive drill holes in coal mines.
  • When coal gets wet, chemical reactions can start resulting in heat generation.
  • When this heat approaches 70°C, devolatalisation commences, flammable gases start to be released,and the coal can spontaneously ignite.
  • This generally is localised but if allowed to spread it can result in a huge loss of resource, excessive smoke and dust and release of green house gasses.
  • A very effective solution is the spraying of a lightweight gypsum foam onto the hot spot, capping it and extinguishing the fire by suffocation and retention of the carbon dioxide at its source of release.
  • Spraying spontaneously ignited coal with water aggravates the problem.
  • During the subsequent washing of the mined coal, the ash and gypsum are removed with the slurry.
  • The equipment is simple. A mixer, foam generation unit, compressor and pump to the spray gun.
  • The gypsum foam can be sprayed from a safe distance. Hot spots can easily exceed a temperature of 1000oC

 

fire

Fire protection Composites

 

Fire rating is the resistance of the material to the transfer of heat from one surface, which is
exposed to a temperature of 1000oC to the unexposed surface. It is measured by the time taken
for the unexposed surface to reacha temperature of 1400C above abient temperature. A futher
measure of performance in fire is the surface spread of flame, toxic emissions and smoke
emission. A Still further rating is the combustibility of the material itself, which is measured by the
increase in temperature in a closed container, into which a specific weight of the material is
introduced when the temperature in the container is approximately 7500 C.

Good performance in fire demands that a material must have refractory properties and also preferably
either a coolant, or a material acting as a thermal insulator or both.

 

fireprotection