Mining Technology: Transactions of the Institutions of Mining and Metallurgy

The conventional disposal of slurried tailings in a tailings storage facility (TSF) leads to the formation of a beach, on which the tailings sort hydraulically, settle, consolidate, and desiccate upon exposure. Basic geotechnical testing, such as specific gravity, Atterberg limits, and particle size distribution, found that there was no particular trend of changes in the tailings properties down the beach. The settled sediment found in a settling test was slurry-like and unsuitable for conventional oedometer testing. Constant rate of loading (CRL) consolidation testing is more representative of the continuous disposal of tailings slurry than conventional step loading. Consolidation testing in a slurry consolidometer was conducted and captured from a slurry-like to soil-like state. A slow rate of loading increased the test time, while a too quick rate of loading built up very high excess PWP. The test results showed different stages of consolidation, depending on excess PWP development and dissipation, and applied stress.

The truck allocation problem is an important section of the transportation system in open-pit mines. Most available models for the truck scheduling problem do not directly address the stochastic nature of truck-shovel systems by using multi-objective optimization techniques. This paper presents a chance-constrained goal programming (CCGP) model based on four important goals to estimate the impacts of the uncertainty on the efficiency of truck-shovel systems. The proposed model has been implemented using 11 schedule scenarios and different confidence levels (CLs) for loader's production to determine the best allocation of trucks in an open-pit copper mine. The results display that the model can handle the quality and quantity of material required to achieve the objectives of the short-term production schedule of the mine in all CLs, even in the highest risk level. This model has a remarkable ability to meet the required objectives in terms of uncertainty in mining operations.

Various indices, notably rock quality designation (RQD), weighted joint density (WJD), and block quality designation (BQD) have been introduced by researchers to survey joints in boreholes, each with its own advantages and disadvantages. The idea of combining WJD and BQD to use positive features of both formed the main goal of the current study, leading to the definition of an improved BQD . After joint surveys of cores drilled in Kulikosh Marble Quarry, Iran, linear regressions validated by statistical tests showed that BQD is less dependent on the drilling direction than the RQD. An empirical equation was also obtained as , with the help of which one can estimate the value of by measuring the original BQD . Taking into account the joint orientations, is logically closer to reality whereby mining engineers can assess block productivity of stone quarries more accurately.

An in situ modification method is used to synthesize a new type of phenolic resin-based composite material used to fill goafs and seal air leaks in roadways. This was followed by scanning electron microscopy, oxygen index, and compression tests. The results show that when the aluminium hydroxide, Sd-31 silicone oil and methylene chloride are added to the phenolic resin in a mass fraction ratio of 8%:5%:3%, the overall performance of the composite material is the best. Compared with unmodified phenolic resin, the oxygen index and compressive strength of thecomposite material are increased by 40.16% and 3.5 times, respectively. The maximum reaction temperature of foaming and curing is also reduced from 120.3 to 87.2°C. To verify the performance of the new material, field tests were carried out at Matigou coal mine in Gansu, China. The average air leakage rate of the working face was reduced from 12.8 to 2.1 %.

New literature, mining regulators, insurance firms, and mining practitioners are calling for increased diligence in the form of real-time monitoring: but what can the industry offer in response? This research establishes a centralisation of instrumentation systems suitable for tailings dams, discussing the specifications, advantages, and disadvantages of each. This paper describes an understanding of dataloggers and sensor nodes, sensor networks, and online monitoring systems critical to the transmission and reception of sensor data across vast and remote site areas. Collaboration with suppliers discovered systems which enable reliable, efficient, and real-time transmission of instrumentation data, ready for interpretation. This paper aims to translate traditionally electrical and systems engineering terminology into a reference base suitable for the broad range of tailings dam practitioners. This reference base is anticipated to help facilitate informed discussions and encourage deployment of appropriate instrumentation systems that are suitable to the practitioner's short- and long-term intent.