Time filter

Source Type

Lower Hutt, New Zealand

Trumm D.,CRL Energy Ltd. | Watts M.,BCRL Energy Ltd
New Zealand Journal of Geology and Geophysics | Year: 2010

Successful passive treatment of acid mine drainage can be improved through the use of small-scale pilot treatment systems to confirm appropriate system selection. Small-scale reducing and alkalinity producing systems were tested at two acid mine drainage sites in the West Coast Region, South Island, New Zealand: the Sullivan Mine and the Pike River Adit. A laboratory trial consisting of a limestone leaching column was conducted on the Blackball Mine acid mine drainage, West Coast Region. All three sites contain low pH (Sullivan Mine, 2.9; Pike River Adit, 3.2; Blackball Mine, 3.1), elevated Fe (Sullivan Mine, 47 mg/ L; Pike River Adit, 34mg/L; Blackball Mine, 10.6mg/L), elevated Al (Sullivan Mine, 14mg/L; Pike River Adit, 1.6mg/L; Blackball Mine, 14.1 mg/L) and minor concentrations of Mn (0.35-0.51 mg/L), Ni (0.005-0.13 mg/L) and Zn (0.14-1.1 mg/L). The percentages of metals removed by the Sullivan Mine reducing and alkalinity producing system were: Fe (97%), Al (100%) and Ni (66%). The percentage metal removals at the Pike River Adit reducing and alkalinity producing system were: Fe (99%), Al (96%), Ni (95%) and Zn (99%). Percent metal removals for the Blackball Mine acid mine drainage were: Fe (87%), Al (91%), Mn (21%>) and Zn (68%). Interpretation of data from these small-scale systems suggests that a reducing strategy may be successful at the Sullivan Mine and Pike River Adit and that an oxidising strategy may be appropriate for the Blackball Mine. © 2010 The Royal Society of New Zealand. Source

Trumm D.,CRL Energy Ltd.
New Zealand Journal of Geology and Geophysics | Year: 2010

Treatment of acid mine drainage can be accomplished by either active or passive treatment systems. Choice between active and passive treatment and appropriate selection of systems within each category is critical for treatment success. In general, active treatment is more commonly used at operational mines whereas passive treatment is typically considered for closed and abandoned mines. Operational mines often have limited space for remediation systems and have large and fluctuating flow rates with changing drainage chemistry as mining proceeds, factors that are addressed more easily with active than passive treatment. In the long term, passive treatment could offer more economic options than active treatment. Various flow charts have been prepared by previous researchers to help select among the passive systems but little work has been done to help select between active and passive treatment or to select appropriate active treatment systems. Furthermore, the passive treatment flow charts have often not included variables important for application to New Zealand sites: topography, climate and available land area. Very steep topography, dense and often protected vegetation, and a high-rainfall climate may result in acid mine drainage with high flow rates in locations with limited space for remediation. This paper presents flow charts specific to New Zealand which have been prepared to accommodate topography and available land area. © 2010 The Royal Society of New Zealand. Source

Ethier A.L.M.,CRL Energy Ltd. | Atkinson J.F.,Jarvis | Depinto J.V.,Limno Technology | Lean D.R.S.,Lean Environmental
Environmental Pollution | Year: 2012

The HERMES model-predicted Hg concentrations and fluxes in Lake Ontario were based on twelve lake and drainage basin variables (i.e., water temperature, precipitation rate, air Hg, surface area, mean depth, water volume, water inflow rate, inflow water Hg, inflow and lake suspended particulate matter, air-water and water-air mass transfer coefficients, and sedimentation rate). The HERMES model-predicted Hg water and surface sediment concentrations were found to be significantly correlated (±20%) with measured values (r 2 = 0.94, p < 0.0001, n = 13) and mechanistic model predictions (LOTOX2-Hg, r 2 = 0.95, p < 0.0001, n = 10). The predictive capacity of HERMES was previously tested on smaller (≤1 km 2) lakes in Nova Scotia and Ontario, Canada (i.e., water and sediment Hg concentrations were ±15% of measured data). Results suggest that HERMES could be applicable to a broad range of lake sizes. Uncertainty analyses on HERMES model input variables indicated a larger atmospheric Hg contribution for Lake Ontario when compared to previous predictions for smaller lakes. © 2011 Elsevier Ltd. All rights reserved. Source

Xu Q.,University of Canterbury | Pang S.,University of Canterbury | Levi T.,CRL Energy Ltd.
Chemical Engineering Science | Year: 2011

Biomass and coal are important solid fuels for generation of hydrogen-rich syngas from steam gasification. In this work, experiments were performed in a bench-scale gasifier to investigate the effect of coal-to-biomass ratio and the reaction kinetics for gasification of chars of biomass, coal and coal-biomass blends. In the gasification of these chars, steam was used as the gasification agent, while nitrogen was used as a gas carrier. The gasification temperature was controlled at 850, 900 and 950 °C. Gas produced was analysed using a micro-GC from which carbon conversion rate was also determined. From the experiments, it is found that the coal and biomass chars have different gasification characteristics and the overall reaction rate decreases with an increase in the ratio of coal-to-biomass. The microstructure of the coal char and biomass char was examined using scanning electronic microscopy (SEM), and it was found that the biomass char is more amorphous, whereas the coal char has larger pore size. The former enhances the intrinsic reaction rate and the latter influences the intra particle mass transportation. The difference in mass transfer of the gasification agent into the char particles between the two fuels is dominant in the char gasification. © 2011 Elsevier Ltd. Source

CRL Energy Ltd. | Date: 2016-01-05


Discover hidden collaborations