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By P B. Schwann

The commonly accepted genetic theories of Pilbara iron ores and Woodie Woodie manganese ores have often presented them as quite unique. This apparent uniqueness is not confined to just iron and manganese, but is also seen in gold and copper deposits in Western Australia. The published material on iron and manganese ores would seem to have either a quite complicated genesis or none at all. An alternate theory for the origin of these deposits is presented which involves a protore with simple oxidation and pH controls with hydrothermal fluid sources from the diagenesis and dewatering of the underlying strata. This theory explains the distribution, thinning, cold dolerites and very high concentrations of deleterious minerals observed in these deposits. This genesis system is also related to the systems that deposit hydrothermal gold and copper in sediments in the region.This paper presents the author’s observations, sampling and mapping after several decades studying and exploring for the minerals in Australia and locations overseas. All of these theories were developed with (or in spite of!) the guidance of Mal Kneeshaw, but would never have seen the light of day without him and the others presenting here. It is not what I would call scientifically polished, and possibly deserves more detailed studies; it is, however, presented as a discussion paper.CITATION:Schwann, P B, 2015. Related genesis for iron, manganese and gold-copper ores in Western Australia, in Proceedings Iron Ore 2015, pp 327–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By C Pope, M Tannock

Mining exploration and development projects in Australia are being negatively affected by the highly complex regulatory and bureaucratic processes at all levels of government. These processes affect mining companies operating in Australia by impacting on timelines and the cost of developing a mining project. It is not uncommon for the granting of project approvals to take in excess of five years, meaning that mining companies struggle with productivity, efficiency, time frame and cost issues in respect to their projects in Australia. As the mining boom in Australia is moving from the investment to the production phase, it is now more important than ever to maintain a regulatory landscape that facilitates rather than discourages new investment.While one of our key arguments is that there is too much burdensome regulation and red tape in Australia, we are also strongly believe that regulatory intervention is necessary to ensure that appropriate checks and balances are in place to serve the public interest and manage environmental, health and safety, social and other development-related impacts that may arise from a mining project. However, the regulatory intervention in Australia has come to a point where it is excessive and starting to discourage valuable investment in mining projects for nominal return to the public. Excessive regulation or ‘red tape’ impedes productivity and competitiveness, deters investment and innovation and costs jobs, all of which ultimately impact on the growth of Australia and the standard of living of all Australians.This paper aims to examine and compare the federal, state and local regulations that govern mining projects in Australia. It will highlight how these regulations are unnecessarily complex, lengthy and duplicated and how they can be streamlined to reduce red tape. In doing so, the paper will evaluate the recommendations proposed by the Productivity Commission Report on Major Project Assessments released in 2013, which include the recommendation to move to a ‘one project, one assessment, one decision’ regulatory model.CITATION:Pope, C and Tannock, M, 2015. Project development and regulation red tape – a comparative analysis: does it need to be so complex?, in Proceedings Iron Ore 2015, pp 621–630 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By P Holtham, K Duffy, L Pyle, W Valery

The mining industry is becoming increasingly focused on pre-concentration due to its potential economic and environmental benefits, particularly for the more complex, low-grade, high throughput operations now being developed. Advances in technology have seen bulk ore sorting (BOS) trialled at several operations. However, BOS should not be seen as a ‘silver bullet’, it can offer significant benefits, but only under the right conditions. Deposits with interspersed mineralogy or disseminated, fine-grained minerals can be difficult for BOS. Large batches of barren or low-grade material are required for BOS to be effective. Hatch has recently completed several studies for clients who believed that bulk sorting was the most suitable pre-concentration technique for their operation, based only on an assumed sorter recovery or on laboratory trials of the chosen sensor. However, minimal consideration had been given to the heterogeneity of the deposit, the achievable separation batch size or sensor repeatability. Evaluation of BOS needs to consider both heterogeneity and sensor suitability. The valuable or gangue mineral must be present in such a way that it can be separated effectively in the large bulk sorting batch sizes, without competing minerals or changing ore characteristics affecting the metal upgrade or recovery. Also, the sensor chosen must be able to detect either the valuable mineral, a proxy for the valuable mineral, or a gangue mineral for rejection with sufficient accuracy and precision (repeatability). This paper presents three recent case studies, emphasizing markers which indicated that bulk sorting was unsuitable for the project whilst highlighting the pre-concentration technologies which were applicable (including particle sorting, and coarse particle gravity separation). The modelling methodology, equipment sizing and forward work plans developed to verify these alternative solutions are also presented, demonstrating the key factors contributing to a thorough scoping assessment.

Aug 24, 2022

By G J. Corbett, T M. Leach

A continued exploration programme has further defined the geology of the Tolukuma vein system, verified the resource indicated by Newmont, and identified potential for additional mineralisation. The resource at Tolukuma Hill, designated as zone C, is a mine recoverable 432,000 t at 18.1 g/t Au & 46 g/t Ag. Mining will be by a combination of open pit and underground at a rate of 100,000 t per annum. Processing will be by SAG mill, gravity circuit and CIL plant. A diatreme breccia, localised at an intersection of structures and a relationship of gold to base metal sulphides, are indicative of a strong porphyry association. Typical epithermal features such as crustiform banded quartz and quartz pseudomorphing platy calcite are also present and locally contain lesser gold mineralisation. Pre-existing dilatant structures have acted as a host to the ore fluids, resulting in the formation of the semi-continuous Tolukuma-Gulbadi veins over a 1100 m strike. A fluid flow model suggests that mineralizing fluids were sourced from a diatreme margin and migrated laterally along dilatant structures. Bonanza gold grades are interpreted to be derived through fluid quenching in the flexure between a hanging wall split, which hosts much of the Tolukuma Hill resource, and the feeder graben structure. Thus, the relationship between the pre-mineral structural geometry and fluid upflow at the margins of a diatreme breccia, controls the ore setting.

Jan 1, 1995

William Frederick McBryde Broun, a graduate of the Royal School of Mines, was employed on the staff of the Mount Morgan Gold Mining Company for some years prior to 1912, and will perhaps be remembered by some of those who attended the Mount Morgan meeting of the Institute in 1910, as an Associate Member present on that occasion. He severed his connection with the Mount Morgan Company in 1912, and was returning to England via the East Indies, when he contracted typhoid atSingapore and died at Colombo.Years later some old papers were being turned out in the office where he had worked, when a set of M.S. notes in his unmistakeable handwriting came to light. On examination these appeared to be the rough draft of a paper he must have beenpreparing for the local branch of the Institute, which he had not been able to complete. The notes were very rough. Apparently it was the author's intention to fill in numerous gaps with extracts from sundry published articles on Cornish mining; theextracts were missing and only the written portions linking them together were there. They give a sketch of Cornish mining practice which those who wish may supplement (as the author would have done) from Le Neve Foster and other well-knownsources. The fragmental notes which have been pieced together as carefully as possible by Mr B G Patterson, Hon Secretary Mount Morgan Branch; are as follows :-The first mine the author worked at was Carn Brea, in 1904."This is one of the largest tin mines in Cornwall, and belongs to the Carn Brea and Tincroft Mining Co, which also owns Cooks Kitchen. The mine was started in 1832, but had been in a bad way for several years previously, and had just begun to recover...

Jan 1, 1919

By D Johns, L Murray

This paper discusses pore pressures in the embankments of tailings dams by comparing real world data with common design assumptions. Assessment of pore pressures has implications on material behaviour interpretation from CPT investigations and, therefore, on the design. For example, the assumption of hydrostatic pressure is conservative for limit equilibrium stability analyses but may be un-conservative in assessing the potential for contractive behaviour and strength loss during shearing. This paper presents some real world data, the investigation methods to determine the pore pressures, and subsequent interpretation of CPT data and material parameters such as the state parameter. It also examines the design implications of assuming a hydrostatic pressure distribution, by comparing results from that assumption with those obtained using the real pore pressures.CITATION:Johns, D and Murray, L, 2018. Characterisation of pore pressure in tailings dams and the implications for design, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 239–249 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Anievas JB, Sevillano AC

This paper describes the acquisition, exploration, development, initial operation and subsequent financing of the Bulawan mine by means of a listing on the Toronto Stock Exchange of a subsidiary of the parent company, Philex Mining Corporation.Located on the island of Negros in the Philippines the property is unique on at least two counts: it is a disseminated gold deposit that occurs in a region of predominantly porphyry copper mineralisation; and it is a gold deposit that is mined by a bulk method of extraction (front and block cave) instead of the normal selective mining methods.

Jan 1, 1997

By R Araya, G Harbort, D R. Seaman, L Huynh, P D. Munro

In today’s operating environment many conventional cleaner circuits struggle to produce final grade concentrate with acceptable levels of non-sulfide gangue and/or penalty elements. This is primarily due to poor selectivity and the entrainment of gangue, and is further exacerbated by the processing of lower grade ores with more complex mineralogy that require finer grinding for liberation. In new concentrators, the standard approach to cleaner circuit design is to define the number of stages of mechanical cells required to achieve the desired concentrate grade. Residence time is the primary factor to size cells and to determine the number of cells required to attain target recovery. While it is required for recovery, a bank of mechanical cells is not the ideal solution to maximise concentrate grade. Relatively coarse bubble size means slow flotation of fines, requiring long residence times. The combination of long residence times and no froth washing means higher entrainment as the pulp becomes more barren and froth stability decreases down a bank.In recent years, the Jameson Cell technology has been retrofitted into a number of concentrators around the world to solve both cleaner circuit capacity and concentrate grade issues. Jameson Cells have been installed at the head of conventional cleaner circuits to produce final grade concentrate in a single step of flotation using a single cell (referred to here as ‘cleaner scalping’ duty). The experience gained from these installations has provided the platform for the design of improved and simpler cleaner circuits that will perform better and be more robust to operate. This paper analyses traditional cleaner circuit designs and explains the philosophy behind new hybrid cleaner circuits, which use Jameson Cells to produce final concentrate and mechanical cells for a ‘cleaner scavenger’ duty. The advantages of the new cleaner circuit design are demonstrated by a case study from an operating plant. Engineering studies show that the better metallurgical performance can be achieved with less equipment than conventional cleaning designs, reducing capital cost, operating cost, and with more than 30 per cent energy savings.Finally, the paper describes simple modifications to the standard laboratory flotation test procedures which accurately simulate this new cleaner circuit using routine equipment.CITATION:Huynh, L, Araya, R, Seaman, D R, Harbort, G and Munro, P D, 2014. Improved cleaner circuit design for better performance using the Jameson Cell, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 141–152 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By S C. Dominy

Gravity amenable gold ores are those that after comminution produce liberated particles, composites and/or carriers that can be recovered by gravity separation means. Recovery depends upon mineralisation type and the comminution and concentration method used. Any in situ ore with more than 20 per cent of gold greater than 100 µm in size is likely to have a strong gravity recoverable component. A less traditional approach is where the gold is sulfide-locked and the gold carrier plus any liberated gold is recovered via continuous gravity recovery following fine crushing. Specific tests are undertaken to determine the level of gravity amenable gold within a deposit. The principal methodology is the gravity recoverable gold (GRG) test, which consists of three sequential liberation and recovery stages. For continuous gravity recovery (CGR), the sample is fed over a laboratory Wilfley table to simulate continuous recovery of the gold. Tails from the feed can be progressively re-ground and re-tabled to develop a grade-recovery curve. Primary geology and gold particle size-distribution have a strong effect on the mass of sample required to provide representative results for both tests. Where low-grade ore contains very coarse gold, substantially larger sample masses are required. Experience has shown that GRG and CGR values can vary throughout an orebody, particularly within different geological-grade domains. A testing regime must consider sample frequency and support.

Sep 5, 2011

By W Midgley, M Torok, I Canbulat, J Katupitiya, S Saydam, S Akdag

The green energy transition is expected to require a range of valuable minerals, which could be supplied through deep-sea polymetallic nodule mining. Deep-sea polymetallic nodules are mineral deposits with a composition well suited to produce lithium batteries, which are expected to be a necessary energy storage solution (Diouf and Pode, 2015; Paulikas et al, 2020) for the energy transition. By 2050 the annual demand for both cobalt and lithium is estimated to increase by around 450 per cent from 2018 levels (Hund et al, 2023), with the annual demand for nickel being greater than 2 million tons, and copper greater than 1 million tons. Polymetallic nodule mining is well positioned to provide these minerals in the near future. An intricate and comparatively unexplored ecosystem thrives within and surrounding the nodule fields (Smith et al, 2008). Deep-sea mining operations have the potential to disrupt and permanently damage this ecosystem through introduced pollution, artificial noise and light, and habitat destruction. Hence, there is a pressing need for new engineering and scientific endeavours to focus on developing new technologies to reduce any environmental impact from mining.

Sep 1, 2024

By A N. Kusnanto, D Sims, L Henim, S Crispin, J Hertrijana

The high sulfidation Purnama Au-Ag deposit located on the Indonesian island of Sumatra entered production in mid-2012 following a two-year program of construction and development. Discovered in 1997 following a regional stream sediment geochemical sampling program by the Normandy Anglo Asia joint venture, it is the first and largest deposit in G-Resource’s Martabe Project to enter production and is the centrepiece of a series of six deposits totalling 8.1 Moz Au and 73.8 Moz Ag in Mineral Resources (G-Resources, 2013a).In 2011 investigation into the controls of high-grade mineralisation in isolated parts of the deposit identified a potentially significant mineralisation style which had not been previously recognised or accommodated in the resource model. An extensive investigation of core and logging data followed to confirm the distribution of the somewhat unusual mineralisation style – a sedimentary-like cavity infill of very high-grade auriferous pyrite within the steep hydrothermal breccia feeders to the system. With the bulk of mineralisation located within the adjacent volcanic sequence and sandy-matrix phreatomagmatic breccia surrounding the feeders, the lack of constraint for high-grade intersections in the hydrothermal breccia zones had potential to significantly impact the mine plan in the lower sections of the planned pit through overestimation of local gold grade. Combined with new data emerging from grade control drilling and infill resource drilling in the pit, a program of reinterpretation of the deposit was initiated to update the geological and alteration framework underpinning the resource model. The result has improved the economics of the project and added metal to the Ore Reserve for Purnama.CITATION:Sims, D, Henim, L, Hertrijana, J, Kusnanto, A N and Crispin, S, 2014. Remodelling the Purnama deposit – an interpretation case study from G-Resources Martabe Project, Indonesia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 229–236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By G S. Beros

In 2019 the Chinese Ministry of Ecology and Environment issued guidelines promoting the implementation of ultra-low emissions in the iron and steelmaking industry. These guidelines aim to drive improvements in air quality through the reduction of particulate matter (PM), sulfur dioxide (SO2) and nitrogen oxide (NOx). Secondly, it also represents an initial means to commence decarbonisation of the industry. The ultra-low emissions guidelines propose that well over 80 per cent of China’s production capacity will achieve these targets by 2025. In response, many sintering operations have implemented numerous improvements to the process that result in significant efficiency gains. Of note is the adoption of deep bed sintering where, with some modifications to equipment, the sintering bed depth is increased resulting in sizable reductions of SO2 and NOx emissions. This paper will also provide an overview of the requirements to introduce deep-bed sintering into an operation and highlight test work completed which quantifies the resultant reduction in emissions.

Nov 8, 2021

Early in 1940 the development and sampling programmes in hand on the North and British Sections of North Broken Hill Limited were such as to necessitate the drilling of a large number of drill holes ranging up to about thirty feet in length. On the British Section, one purpose was to test the existence, width, and value of narrow lodes believed, for geological reasons, to occur in the walls of the existing workings. Another object was to definitely disprove the existence of payable shoots of ore in certain largerhodonite and quartz-garnet ("garnet sandstone") pillars which had been formerly left as unpayable.On the North Section, the main purpose of the short holes was to delineate the ore-body boundaries by drilling laterally from drives in ore, and thus enable level layout to be planned in advance of sill stoping. It was also desired to test the walls of stopes in those portions of the mine where the economic limit of mining is not rendered obvious by a clear-cut wall, but should be determined by assay. In these latter cases it was hoped to eliminate "prospecting by stoping," a procedure by which any doubts as to the existence of further good ore behind the low-grade walls were settled by continuing to stope laterally until all chance of such an occurrence was removed.LONG HOLE ROCK DRILLINGFollowing an investigation of recorded instances of similar practice elsewhere it was decided to use the rock drill for a series of trial sample holes. A 3-in. drifter was used. This was selected from those in use underground, and was given a special overhaul; had a new machine been purchased, a 4-in. type would probably have been obtained as being more suited to the work. The rods were H in. hollow round steel with a type "1" Jackrod thread. Couplings were of chrome steel, and were H in. in diameter, and 2 in. long. Jackbits (type "1" thread) in sizes from 2 in. to 4 in., with 1-in. gauge changes, gave a range of nine bit sizes. They were resharpened by hot milling, and were not milled to a definite gauge size.After sharpening, bits were sent underground without sorting into sizes, the drillers selecting the next bit with callipers. In view of the small scale of operations, it was not considered worth while to adopt special measures, such as the cold grinding of bits, which might have given a better product. Later, however, new bits were used exclusively, the idea being to accumulate enough blunt Jackbits to warrant a thorough treatment of the sharpening...

Jan 1, 1941

By M Dean, M Nehring, P Knights, M S. Kizil

Integrated continuous mining techniques such as fully mobile in-pit crusher and conveyor (FMIPCC) systems offer inherent labour, energy and environmental benefits to deep pit metalliferous mines. However, before such systems become commonplace, a number of barriers must be overcome.This paper outlines a number of commonly perceived barriers to FMIPCC application, together with a number of suggested solutions. The paper advances a design approach for specifying FMIPCC systems for deep pit metalliferous applications. A novel FMIPCC configuration is advanced using a hydraulic excavator in backhoe configuration. Because of the requirement to minimise belt extensions, a mine planning approach is presented based on a series of parallel and radial belt conveyor moves.The FMIPCC system does not fully replace truck-shovel systems. In the proposed mine plan, sinking is undertaken with truck-shovel systems using a series of box cuts, whereas pit ‘widening’ activities are accomplished via the FMIPCC system. Because of inherent differences in mine sequencing, the net present value derived from the FMIPCC mine will differ markedly from that derived from traditional, nested-pit, truck-shovel mining approaches. Therefore, any comparison of the FMIPCC and truck-shovel approaches must take into account radically different mine planning approaches.CITATION:Dean, M, Knights, P, Kizil, M S and Nehring, M, 2015. Selection and planning of fully mobile in-pit crusher and conveyor systems for deep open pit metalliferous applications, in Proceedings Third International Future Mining Conference, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The objectives of this paper are to introduce the International Code of Practice for Risk Management of Tunnel Works and to illustrate to the participants of the 13th Australian Tunnelling Conference 2008 how the insurance industry would like to see the future of tunnelling insurance. Tunnel construction projects have suffered large losses over the years as can be shown from various loss examples and a list of major losses over the last ten to 15 years. Since the consequences of insufficient risk control had to be borne by insurers, these losses have heightened the need for improved and adequate risk management measures so that insurance cover can also in future be provided for this hazardous industry sector. Observations are made as regards to the prevailing trends in the tunnelling industry, which contribute to the increase in risk and have adverse consequences for the insurance industry. To find a solution to this dilemma various options are examined with the suggestion of a Joint Code of Practice for Tunnel Works being agreed by all stakeholders, which would become essential to secure future insurance protection for such project work. The British Tunnelling Society has, in cooperation with the Association of British Insurers, developed such a code, which the International Tunnelling Insurance Group has now adopted for global application in international markets. The content and concept of this code is explained to establish a framework of understanding and applied risk management principles for tunnel works. This initiative also has the support of the International Tunnelling Association and the International Association of Engineering Insurers. The international application of this new code is demonstrated with a few examples, which also includes Australian projects. It is the aim that this code forms in future part of the insurance coverage for tunnelling works in order to put this risk segment on a more sustainable basis. For that reason the insurance industry is seeking the support of all stakeholders of tunnelling construction projects.

Jan 1, 2008

By W Valery, A Jankovic

The ball mill in closed circuit with hydrocyclones is an industry standard, and well known methodologies exist for equipment sizing, selection and design. However, the potential to improve the capacity of ball mill circuits by replacing cyclones with screens has been recognised for many years and recently has been successfully realised, thanks to developments in fine screening technology. Proper methodology for equipment sizing and selection is required to capitalise on this opportunity, but there is currently insufficient information and few guidelines available on how to design such a circuit. This paper discusses the differences between ball mill circuits closed with cyclones and with screens. A methodology is described for equipment sizing and selection for a circuit closed with screens, and the laboratory testing requirements are described for low grade base metal ores and magnetite ores. An economic evaluation is also presented for a case study demonstrating the potential benefits of closing a ball mill circuit with screens.CITATION:Jankovic, A and Valery, W, 2013. Energy efficient ball mill circuit - Equipment sizing considerations, in Proceedings MetPlant 2013 , pp 285-295 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By C Smith, J Cilliers, K Hadler

Unstable flotation froths, that burst before they overflow, produce no concentrate. Increasing the froth stability to improve recovery is therefore an obvious control strategy. Froth stability can be measured readily as the fraction of air entering the flotation cell that overflows as froth, rather than bursting on the surface; the ‘air recovery.’ Air rate is one of the most significant variables affecting froth stability. It is interesting that froth stability (air recovery) is maximised at a specific air rate, above or below which it decreases. It is important for metallurgists to realise that this maximum froth stability also produces the maximum mineral recovery, without compromising concentrate grade. Flotation cells must be operated at the air rate that produces the highest air recovery. The peak air recovery (PAR) to maximum mineral recovery relationship was first demonstrated by Hadler and Cilliers in 2009. Since then, the relationship between PAR and flotation performance has been widely explored; varying air rate, froth depth and particle size. Industrially, reducing the flotation bank air rate to achieve PAR yielded better mineral recoveries than other down-the-bank air rate profiles. In this paper, we present an overview of these key developments and findings in flotation optimisation based on PAR. Furthermore, using new industrial data, we show that PAR is not just applicable to rougher-scavenger cells, but also to flotation columns. Finally, we consider the future application of such an optimising control concept. CITATION:Smith, C, Hadler, K and Cilliers, J, 2018. Flotation control using froth stability: past, present and future, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 441–454 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By P Vasconcelos, X D. Deng

Numerous supergene manganese oxide deposits are developed inSouth China as a result of weathering of a thick sequence of Paleozoic marine Mn-bearing sedimentary rocks, consisting mainly of limestones, cherts and black shales that were intensely folded and faulted due to multiple episodes of tectonism since the late Triassic. The ore minerals are dominantly pyrolusite, cryptomelane, nsutite, lithiophorite and braunite. The supergene manganese ores contain Mn ranging from 20 to 44 wt per cent; manganese oxide deposits derived from cherts and black shales also contain recoverable levels of Co, Ni, Cu, Pb and Zn. 40Ar/39Ar dating of potassium-bearing manganese oxides reveals that extensive supergene manganese ore formation started at least in the earliest Miocene and persisted to the Present. Ages of the deposits show a close correlation to tectonic stability, with the oldest in tectonically quiescent areas and the youngest in active areas that have subjected to continuous uplift and thus significant denudation. The prolonged wet and hot climate since Oligocene and the balance between weathering and erosion, which is parameter to the tectonic stability, are the ultimate controls on the formation and distribution of South China supergene manganese oxide deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Upgrading of a Flow Sheet Selection PC Algorithm for Refractory Concentrates Treatment

Sep 13, 2010

By J Krnmmelbein, T Raab

In Lusatia, lignite mining causes major disturbances on the landscape scale. Reclamation procedures are applied to recover the reconstructed landscape for different land use options. In this study we investigate soil physical properties of an agricultural reclamation/recultivation site directly after site restoration and the development of selected parameters within the first years after site restoration depending on varying recultivation strategies.The sandy substrates used for recultivation stem from depths of several meters. They are unstructured, free of recent organic matter and have high contents of calcium carbonate. During reconstruction and most of all during surface levelling with heavy crawlers, the substrate?undergoes high mechanical stresses. This leads to partly severe soil or substrate compaction, depending amongst others on substrate water content and mechanical stresses during site construction. We investigate the effect of different organic soil amendments, different crop rotations and partly subsoiling on the development of soil structure. We compare results of laboratory measurements directly after site construction before any reclamation measures had been applied to results we gained after three and four years of recultivation. The results show that after the earthworks are completed, the site is strongly heterogeneous in relation to mechanical stability, permeability for air and water, pore volume and bulk density. The results after three and four years show that the heterogeneity of soil physical parameters decreases. The selection of suitable crop rotations superimposes the affects of other reclamation measures, eg varying organic fertilisers or deep loosening.CITATION:Krnmmelbein, J and Raab, T, 2012. Reclaimed lignite mining areas A73 in Lusatia - Development of soil physical parameters of an agricultural site within the first years after site reconstruction, in Proceedings Life-of-Mine 2012 , pp 117-122 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012