Coal, Oil & Gas
The Szego Mill™ makes environmentally friendly fuel possible.
Our patented Ash Reactivation process can remove nearly 100% of ash from coal and reduce pyritic (sulphur) content by 65%. Your coal-cleaning equipment costs can be reduced by 70%. Energy consumption can be reduced by 40%. CO2 emissions of an average 35MWt boiler can be reduced by 18,000 tons per year.
Wet-grinding wasted ash product with the Szego Mill™ captures harmful Sulphur oxides, doubles calcium utilization, reduces disposal costs, and prevents thousands of tons of greenhouse gases while at the same time saving up to $500,000 in yearly limestone costs for a typical pilot-sized boiler installation.
The Szego Mill™ can create clean burning Coal-Oil-Mixture slurry fuel at cost of $3.70 vs. $15.20 of oil per 1M-BTU / 1055MJ (2008 prices) using recovered waste product, or even less using recovered biomass oil instead of petroleum.
Simultaneous grinding and oil agglomeration in the Szego Mill™ offers major equipment simplifications and cost reduction. The largest size Szego Mill™ – 2' diameter × 6' high – processes 30t/h of coal at about 30 kWh/t. A comparable ball mill is 7' × 12', uses 220 kW (300hp), and requires a special reinforced concrete floor to support the weight of 26 tons of balls.
This paper deals with the mechanism of breakage of Pittsburgh coal in the Szego mill, for the preparation of coal- grade 2 oil and coal-water slurries. The kinetics of coal breakage is discussed. The non-first-order breakage in the mill is due to material and environment effects. A two-component mechanistic model, considering the coal in a size interval to be composed of crushed feed particles and flaky particles, is used to explain the breakage.
This paper was made available by our associates and is not authored by Szego Materials Engineering. We offer it to our customers for relevance to processes using the Szego Mill™.
This paper presents a general solution of how to link together the treatment of different solid waste: excess sludge, wastes glycerol or fishery residues and waste ash. The aim of the solution is to enhance biogas production and to produce an organic–mineral suspension fertiliser. The enhancement of biogas productivity is achieved by adding waste glycerol from biofuel plants or fish residues from fish farming and fishing industries into anaerobic reactors of wastewater treatment plants. The enhancement of biogas productivity lies in the range of 200–400%.
Recent work on coal beneficiation by simultaneous grinding and oil agglomeration in the Szego mill is reviewed.
In brief overview, the spherical agglomeration technique developed at the National Research Council of Canada (NRCC) is an excellent method for cleaning and recovering very small coal particles. A process improvement described involves grinding the coal with the Szego mill in water, with simultaneous addition of an appropriate amount of oil. Thus, a simpler, single operation replaces the grinding and agglomeration steps of the NRCC process and the energy expended while grinding is also used for mixing and agglomeration. Significant savings in equipment and power consumption were reported.
Grinding of coal in oil for COM fuel preparation is simpler and may give better slurry properties than dry grinding followed by dispersal in oil. Different coals have been ground with the novel Szego mill in oil over a range of operating conditions. When the coal has a high ash content and beneficiation is required, grinding can be carried out in water, followed by oil agglomeration of the coal particles to prepare the COM fuel.
A mean particle size down to about 15µm is readily obtained using the Szego Mill, at reasonable capacity and power consumption. Aspects of mill scale-up are discussed.
The flaky nature of its products gives the Szego mill a potential advantage over other grinding equipment in mineral matter liberation. The stability of coal-oil, coal-water or other slurries is enhanced due to the decreased settling rate of such flakes. Throughput of the existing small Szego mills (22 cm I.D.) is high, ranging between 200-500 kg/h of coal for a product median size of 15-30µm, from a feed size of -1/4".
The initial boulders have been transformed into large flakes due to the rolling action inside the mill. A wide variety of product specifications can be met by appropriate combination of design choices and operating conditions.