International journal of mine water

This paper summarizes a contract report of work undertaken on behalf of the Department of Energy, Mines and Resources to ascertain the effectiveness of surface applied chemicals as a swelling retardant for use in underground coal mines. It addresses the mineralogical, chemical and mechanical aspects of the swelling clay problem. The experience of the use of swelling retarders in the oil well drilling industry is reviewed and the various types of stabilizing chemicals discussed. Finally, potential applications of the technology in coal mining are discussed with mention of the toxicity of the chemical agents and their relative costs.

Characterization of the pollution charge of drainages from pyrite mines of Aljustrel (Portugal) was made. Laboratory experiments were performed in order to recover copper by cementation and remove iron, zinc and acidity by neutralization with lime. It was found that the removal of the metal ions is completed when pH reaches a step at 5.0–5.5, whichever the ratio between Fe(II) and Fe(III).

A survey of ochreous discharges from former coal mines in the UK indicated ammonia contamination at 2–5 mg/L in water from flooded shafts of depths >400–800 m. Although significant, this was much less than historically observed in working mines. No correlation was observed between ammonia and iron concentrations. However, ammonia was removed to some extent in constructed wetlands designed primarily to remove iron. A mechanistic study of wetland removal of ammonia from mine water indicated the main process to be bacterial nitrification, similar (despite great differences in operating conditions) to that occurring in many wastewater treatment works. The study was based on water containing 4–5 mg/L ammonia and some 12–27 mg/L iron from the abandoned Woolley mine in Yorkshire. Notwithstanding relatively high salinity and short residence time, most of the ammonia entering the wetlands was, at least initially, converted to nitrate. Field measurements showed that the conversion efficiency was increased at lower flow rates, higher temperature, and longer flow stabilisation, which are all consistent with bacterial action. Subsurface flow conditions were simulated in column studies, using pre-sterilised gravel and mine water taken from the wetland cells; two strains of bacteria commonly associated with nitrification in domestic wastewaters, Nitrosomonas europaea and Nitrobacter agilis, were able to reproduce the 89% ammonia oxidation observed in the wetlands. It was concluded that the high degree of aeration, neutral pH, and nutrient content of the mine water greatly favoured nitrification. Although more saline and lower in biochemical oxygen demand than organic wastewater, nitrification was not inhibited.

Water can mean many different things to different people. As an essential of life it is taken for granted., but to the mining engineer it can be a serious hazard a costly item in production. We can not afford to take it granted. It must involve us in fundamental engineering/economic studies to achieve optimal operations and is an area we can not afford to neglect.

Nam Phi sẽ luôn cần những lỗ khoan thăm dò sâu để đánh giá những mỏ tiềm năng mới. Các khảo sát địa chấn và các khảo sát địa vật lý khác cung cấp các công cụ hữu ích cho nhà địa chất thăm dò nhưng không thể thay thế một mẫu lõi vật lý. Các công ty nhà thầu và cung ứng cần tập trung vào các kỹ thuật và thiết bị cung cấp khả năng khoan nhanh hơn và giảm thiểu rủi ro. Sự biến động giá vàng và tác động lên doanh thu của các công ty tài chính khai thác mỏ tài trợ cho các dự án thăm dò gây ra sự thay đổi trong mức độ hoạt động khoan. Tuy nhiên, việc khoan thăm dò sâu cho vàng là một phần không thể thiếu của ngành công nghiệp khai thác mỏ Nam Phi và sẽ tiếp tục như vậy.

Marine wastes extract (MWE), prepared from marine organic wastes, was used to develop an alternative nitrogen source for sulfate-reducing bacteria (SRB) in environments like acid mine drainage that are acidic in nature and contain high levels of sulfate and dissolved metals. The MWE contains 13.95 g L−1 of nitrogen, and other micronutrients like K, Na, P, S, Ca, Fe, Mg, Mn, Zn, Co, Cu and Ni, and has a C/N ratio of 0.107. A modified SRB medium (MSRB) was developed by replacing the commercial nitrogen source of standard SRB growth medium with MWE. MSRB was compared with modified Postgate B, Postgate B, and Widdel and Pfennig media, which contained bactopeptone and NH4Cl, as nitrogen sources. Results showed that the growth media could support a total microbial population of 2.8 × 1012–6.2 × 1012 cells mL−1 with 96, 80, 92.5, and 65 % SRB in MSRB, Postgate B, modified Postgate B, and Widdel and Pfennig media, respectively. The sulfate reduction efficiency was 97, 87, 72, and 68 % at reduction rates of 12.41, 11.10, 4.35, and 8.8 mg L−1 h−1, respectively, for the same media. We conclude that MWE could be a cost-effective substitute for commercially available nitrogen sources for SRB for large-scale treatment of sulfate-rich wastewater.

The sustainability of irrigation with gypsiferous mine water and different irrigation management practices was evaluated using a milti-disciplinary approach, where crop response was investigated along with the impact on soil and groundwater resources. Field trials carried out at two mines (Landau and Kleinkopje Colliery, Mpumalanga Province, South Africa) indicated that a wide range of species can be cropped for commercial purposes under irrigation with this water. Chemical analyses of groundwater underlying irrigated areas indicated that contamination of groundwater did not occur after three years. The results of a glasshouse trial indicated that the inclusion of NH4 + for N-fertilization in a NO3 −-NH4 + ratio of 2:1 to 1:1 is advantageous to root and top growth of wheat. According to simulations run with the Soil Water Balance (SWB) model and the CLIMGEN weather data generator, soil chemical and physical properties will not be irreparably damaged after thirty years of irrigation. Perennial pastures, irrigated at high frequency, provided the highest net farm income and water utilization.