[en] This article gives an overall review of the main achievements in filling mining methods abroad. With especial reference to China's specific conditions, the author offers his proposals to China

[en] Technical innovations which have been used in success in the cut-and-fill stoping for mining some gradually inclined uranium ore bodies are described with stress on how to economically tackle with some main problems encountered - the requirement of two or even more production streams of development and cut-and-fill, the complicative supervision for roof control, and high work-load in defining assay boundaries of bottom walls. (Author)

[en] In the Review Statement and Evaluation of SKB's RDandD programme 2007 (SKI Report 2008:48E), the former Swedish Nuclear Power Inspectorate (SKI) commented that considerable work remained to be done for knowledge of both practical management issues on backfilling and analysis of long-term backfill evolution to reach the same level as for the canister and the buffer. SKI considered that the backfill material had not been thoroughly reported in the RDandD programme. More concrete plans were also needed relating to large-scale demonstration experiments to investigate the performance of the backfill in as realistic conditions as possible. In the spring of 2009, noting that SKB had changed its concept for backfilling several times over the last few years, and after having visited SKB's most recent backfilling trials at Aespoe, both SSM and SSM's expert group BRITE had strong concerns regarding SKB's programme for backfilling the repository tunnels. Although the BRITE expert group has been keeping a watching brief over SKB's development work on backfilling, SSM has not undertaken a systematic assessment of SKB's work in this area since the SR-Can Safety Report was reviewed in 2006. Dr David Bennett, a member and secretary of the BRITE expert group, was asked to do such an assessment. This report describes the assessment results

[en] The article introduces the successful experiences from the practice of mining method of upper layers of filling in Ganzhou Uranium Mine from the aspects of technical applications and technological improvements. The directions are pointed out for the developments in the future. (authors)

[en] In this paper we analyze the behavior of a gang-scheduling strategy that we are developing for the ASCI Blue-Pacific machines. Using actual job logs for one of the ASCI machines we generate a statistical model of the current workload with hyper Erlang distributions. We then vary the parameters of those distributions to generate various workloads, representative of different operating points of the machine. Through simulation we obtain performance parameters for three different scheduling strategies: (i) first-come first-serve, (ii) gang-scheduling, and (iii) backfilling. Our results show that backfilling, can be very effective for the common operating points in the 60-70% utilization range. However, for higher utilization rates, time-sharing techniques such as gang-scheduling offer much better performance

[en] Study of fine-particle media, because of their high sorption capacities, is of particular importance for the use as backfill materials in waste repository design, and because argillaceous formations are particularly suitable as host rock formations. In this study, sorption and retardation characteristics of strontium in fine-particle media were studied to evaluate the distribution coefficient (Kd) and retardation factor (Rd) of this radioactive element in fine-particle media, which was comprised of selected particles with a diameter less than 1 mm from a candidate site to dispose very low level waste (VLLW). The results indicated that Kd values of strontium under different initial concentrations ranged between 20 and 110. Values of strontium Rd measured from column experiments ranged between 36 and 102, with the corresponding Kd values, determined from solving the inverse problem of Rd calculating formula, ranging between 5 and 20. In conclusion, the Kd value of Sr from the batch tests was found to be higher than these from the column experiments. (author)

[en] The rheological and mechanical properties of a Ca-smectite have been investigated by different laboratory tests. By these tests the permeability, the water uptake properties, the swelling properties, the swelling pressure, the stress-strain properties, the strength and the creep properties have been determined. The influence of density, temperature, time and stress level have been considered. Mathematical models of the measured properties and behavior of the clay have been suggested so that calculations involving mechanical and rheological scenarios can be made. The behavior of the clay have been discussed with reference to the microstructure and comparisons between the investigated Ca-smectite and a Na-smectite (Mx-80) have been made. One main conclusion is that the difference between the properties and behavior of Ca-smectite and Na-smectite is small at densities >2.0 t/m³. At densities <2.0 t/m³ the difference is increasing with decreasing density. (orig./HP)

[en] A back-filling method by excavating chamber to get filling materials and its application in a uranium mine are introduced. The conditions of ore block amenable to adopt this method, and the principles and conditions of the location selection of the chamber are discussed. (authors)

[en] Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

[en] With the low permeability and high swelling property, Gaomiaozi (GMZ) bentonite is regarded as the favorable candidate backfilling material for a potential repository. The diffusion behaviors of HTO in GMZ bentonite were studied to obtain effective diffusion coefficient (D_e) and accessible porosity (ε) by through- and out-diffusion experiments. A computer code named Fitting for diffusion coefficient (FDP) was used for the experimental data processing and theoretical modeling. The D_e and ε values were (5.2-11.2) x 10^-11 m²/s and 0.35-0.50 at dry density from 1,800 to 2,000 kg/m³, respectively. The D_e values at 1,800 kg/m³ was a little higher than that of at 2,000 kg/m³, whereas the D e value at 1,600 kg/m³ was significantly higher (approximately twice) than that of at 1,800 and 2,000 kg/m³. It may be explained that the diffusion of HTO mainly occurred in the interlayer space for the highly compacted clay (dry density exceeding 1,300 kg/m³). 1,800 and 2,000 kg/m³ probably had similar interlayer space, whereas 1,600 kg/m³ had more. Both D_e and ε values decreased with increasing dry density. For compacted bentonite, the relationship of D_e and ε could be described by Archie's law with exponent n = 4.5 ± 1.0. (author)