Coal Processing
Alternative uses of coal in the production of advanced materials and lightweight products for the sustainability of the South African coal industry
2023
Desktop review commissioned to shape a five year coal processing research roadmap, covering rare earth recovery, carbon fibre, graphene, activated carbon and building products. For research planners.
What this report foundCoal can feed products well beyond combustion. The study sets out routes to rare earth elements held in particular seams, building materials made with carbon...
R1500,00
Coal can feed products well beyond combustion. The study sets out routes to rare earth elements held in particular seams, building materials made with carbon fibre and carbon char, coal foam and graphene composites, carbon black and activated carbon, including a coal derived activated carbon reported to hold four times the gas of compressed natural gas at lower pressure.
Beneficiation of weathered ultra-fine discard with an advanced High internal phase water-in-oil technique
2022
Laboratory flotation test work on five weathered discard samples, comparing an emulsion binder with kerosene and optimising dosage and agitation speed. For plants looking at fine discard dumps.
What this report foundA high internal phase water in oil emulsion binder upgraded weathered ultra fine coal discard.
R1500,00
A high internal phase water in oil emulsion binder upgraded weathered ultra fine coal discard. At 5 kg/ton on a feed of 29.34 per cent ash and 20.94 MJ/kg, flotation gave a clean coal of 11.76 per cent ash and 28.61 MJ/kg at 15.61 per cent mass yield. Calorific value rose with agitation speed and fell with binder dosage.
R1500,00
Cost Evaluation of Different Medium Solids for Air Dense Medium Fluidized Bed Coal Separation
2017
University laboratory work on air fluidised bed separation, testing pyrrhotite, blast furnace slag, silica sand and coal discards against magnetite, for engineers considering waterless coal washing.
What this report foundMagnetite and pyrrhotite each gave the most uniform and stable fluidised bed densities, with bed density variation under 0.7 per cent.
R1500,00
Magnetite and pyrrhotite each gave the most uniform and stable fluidised bed densities, with bed density variation under 0.7 per cent. A pyrrhotite and magnetite blend at a weight ratio of 40:60 beat magnetite alone, producing a product of 14.50% ash and 27.30 MJ/kg from a feed of 39.27% ash and 18.76 MJ/kg.
Demonstrate the efficiency of UAV-GPR for assessment of rehabilitation sites and detection of subsurface cavities
2023
Field trials at two South African collieries comparing drone mounted ground penetrating radar against ground based surveys, for measuring rehabilitation soil thickness and locating shallow voids. For rehabilitation teams.
What this report foundGround based radar mapped rehabilitation soil profiles well enough to replace much of the auger sampling normally needed, and a 100 MHz system picked out...
R1500,00
Ground based radar mapped rehabilitation soil profiles well enough to replace much of the auger sampling normally needed, and a 100 MHz system picked out anomalies at about 5 to 6 m depth that were likely old mining voids and related subsidence. Penetration below roughly 6 m needs lower frequencies, which cost resolution and require larger antennas.
Dense-medium Fine Coal Processing: Tests Conducted at South Witbank Coal Mine
2003
Pilot scale dense medium testing on fine coal at a Witbank colliery after the plant was moved from an earlier site, with sampling, efficiency and magnetite results for plant designers.
What this report foundThe fine coal dense medium pilot plant was rebuilt at South Witbank Coal Mine and run on fine coal, with tests covering single, double and three stage...
R1500,00
200319 pages
The fine coal dense medium pilot plant was rebuilt at South Witbank Coal Mine and run on fine coal, with tests covering single, double and three stage processing, the effect of recirculating load, magnetite size and losses, separation efficiency and continuous operation. The fast screen could not deliver the required capacity and was replaced by dewatering cyclones to deslime the feed.
Development of a Horizontal Winnower for the Beneficiation of Fine Coal
Proof of concept work on dry beneficiation of minus 6 mm coal, combining airflow modelling and simulation with a laboratory winnowing box, for plants short of process water.
What this report foundHorizontal air winnowing separated fine coal by particle size and density in laboratory experiments, supported by equation of motion modelling and...
R1500,00
Horizontal air winnowing separated fine coal by particle size and density in laboratory experiments, supported by equation of motion modelling and computational fluid dynamics. Modelling indicated that a chamber 0.6 m high and 1 m long is sufficient to displace any minus 6 mm particle at air velocities of 10 to 30 m/s.
Dry Processing of Coal – Progress Report: Tests Conducted on the IMS / Slater Coal Marketing Allair Dry Jig
2016
Test work on a dry jig installed at a Balmoral site, covering coal sized below 50 mm and duff below 12 mm, for producers considering waterless beneficiation.
What this report foundA 30 tonne per hour pilot Allair dry jig upgraded run of mine coal to thermal coal specification, but could not effectively beneficiate finer duff.
R1500,00
201613 pages
A 30 tonne per hour pilot Allair dry jig upgraded run of mine coal to thermal coal specification, but could not effectively beneficiate finer duff. Cut point densities and EPM values matched other dry processing equipment, though the jig appeared to give better control of the parameters governing separation. Four tests ran on run of mine coal and two on duff.
Dry Screening Tests Conducted With a Bivi-tec Screen
2008
Screening trials at two South African collieries, one on a small test unit and one on a full scale installation, for plant staff handling fine, damp coal.
What this report foundFine coal was screened at small apertures while surface moisture stayed below about 5 per cent.
R1500,00
200820 pages
Fine coal was screened at small apertures while surface moisture stayed below about 5 per cent. Above that, fines adhered to the coarser particles and screening became very difficult. The dual vibrating polyurethane mats stopped blinding and clogging, so screening area stayed available, but the screen action still could not dislodge fines from very damp coal.