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By Gerald W. Elger

Research at the Albany Metallurgy Research Center has shown that high-purity rutile can be produced from relatively low-grade ilmenite obtained from a massive rock deposit. Ilmenite is first smelted in an electric-arc furnace to separate the iron and produce a slag enriched in titanium dioxide. Titania slag mixed with a phosphate flux is then oxidized to synthesize rutile and form a phosphate-glass matrix which contains the impurities. Attrition scrubbing the treated slag in dilute solutions of phosphoric or sulfuric acid liberates the rutile, which is concentrated by physical methods. Tests show that synthesized rutile containing 95 to 97 pct titania responds to chlorination at the same rate as natural rutile.

Jan 1, 1973

By Mason L. Dicks

For many years The Hanna Mining Company has been investigating the flotation of the non-magnetic iron ores located in the Western Mesabi Range of Minnesota.1 During the 1950's a number of anionic iron procedures were evaluated and in the late 1950's and early 1960's the anionic silica floats and the cationic silica floats were tested with improved results.2 The cationic float became more attractive and effective by the use of the improved ether amines. About 1962 a desliming process by selective flocculation was developed by the U.S. Bureau of Hines at Minneapolis', Minnesota.3, 4, 5 This is a very efficient method of desliming and was first tried with the anionic silica float and then the more practical cationic silica float. In the mid 1960's The Hanna Research Laboratory began studies to optimize the selective flocculation process for our ores. This was followed by studies to optimize the cationic silica float after desliming by selective flocculation. This testwork was done on large, 500 to 1000 tonne bulk samples of oxidized taconite which were later successfully piloted at .68t/h (1500 Lbs. /hr.). A program was then begun to test the oxidized portions of numerous taconite drill holes to outline the ore bodies and develop mining plans. This paper will discuss our optimization results of both the selective flocculation and the cationic silica float as applied to our various ores. In addition the pilot plant studies and drill core testwork will be discussed.

Jan 1, 1978

By John L. Shafer

Often an in situ leach is the only practical economic method for copper recovery from small low grade oxide deposits. The decision to develop a copper property by an in-situ blast and leach is strongly dependent on ore grade, tonnage, hydrology, and the copper extraction and acid consumption rates. The inherent "leachability" of the ore will in part determine the desired amount of fracturing of the ore deposit by the blast in order to obtain a copper extraction rate that is economical. For the last several years Occidental Research Corporation (ORC), the corporate R&D for Occidental Petroleum has under-taken a modest effort to address the question of "how to best identify and determine the information necessary to predict and control the operation of an in-situ leach for the economic recovery of copper."

Jan 1, 1977

By G. Mbuyi Kamba

Literature is rather abundant on the topic of steady-state network analysis programs. Many versions exist, some of them have real extended facilities such as full graphical manipulation, fire simulation in motion, etc. These programs are certainly of great help to any ventilation planning and often assist the ventilation engineer in his operational decision making. However, what ever the efficiency of the calculation algorithms might be, their weak point still is the overall validity of the model. This numerical model, apart from maybe the questionable application of some physical laws, depends directly on the quality of the data used to identify its most influencing parameters such as the passive (resistance) or active (fan) characteristic of each of the branches in the network. Considering the non-linear character of the problem and the great number of variables involved, finding the closest numerical model of a real mine ventilation network is without any doubt a very difficult problem. This problem, often referred to as the parameter adjustment problem, is in almost every practical case solved on an experimental and "feeling" basis. Only a few papers put forward a mathematical solution based on a least square approach as the best fit criterion. The aim of this paper is to examine the possibility to apply the well-known simplex method to this problem. The performance of this method and its capability to reach the global optimum which corresponds to the best fit is discussed and compared to that of other methods.

Jan 1, 1995

By Robert L. Runkel, Kenneth E. Bencala, Briant A. Kimball, Katherine Walton-Day

The solute-transport model OTIS and the reactive solute-transport model OTEQ were used to simulate geochemical conditions in Cement Creek, a tributary to the Anirnas River in Colorado. OTIS was used to depict instream zinc concentrations, and to simulate the effects of two remediation scenarios on zinc concentrations at the mouth of Cement Creek. These simulations do not account for effects of changing stream pH on metal concentrations. Preliminary simulations using OTEQ to account for instream pH changes were unsuccessful due to the spatial nature of mixing processes, and insufficient information about the thermodynamic properties of precipitates forming in mixing zones.

Jan 1, 2000

By A. Supomo, A. Partanen, M. Mular

Although many SAG operators may agree that on-line measurement of SAG feed-size is an attractive notion, applying this information in a control strategy that recovers the investment, engineering time, and maintenance is not necessarily straightforward. The P. T. Freeport Split-Online system was justified based on the assumption that SAG feed-size could be used in a feed-forward control strategy either at the regulatory or expert system control level. Something like “as the feed size changes adjust the throughput to avoid under or overloading the mill” was envisioned. However, following installation and calibration, Cluster Analysis showed that such an approach would not be successful. However, the sensor has been successfully integrated into Freeport’s grinding control strategy other ways. It provides an input to the Kalman filter parameter estimator used in a model-based control strategy that optimizes throughput and grind. The Split sensor also provides a characteristic feed size parameter for use in an on-line work index estimator. This paper describes the calibration and installation of the Split SAG feed-size analyzer, and reviews the evolution of its use in the Freeport C3 grinding circuit control strategy.

Jan 1, 2001

By M. Kul

In this study, the effects of various extraction and stripping parameters, such as equilibrium pH (7.0, 8.5 and 10), extractant concentration (5, 10 and 20 volume %), organic-to-aqueous (O/A) ratio and stripping agent type and concentration were studied on chromium (VI) recovery from chromium electroplating rinse bath wastewater using Aliquat 336. Results showed that these parameters all had significant effects on chromium (VI) recovery. A pregnant strip solution from a chromium electroplating rinse bath wastewater with 33.4 g/L chromium content, suitable for sodium dichromate production, was generated by 20 vol. % Aliquat 336 in commercial kerosene. The O/A ratio was 1/4 and the equilibrium pH value was 0.87, the as-received pH value. The wastewater was treated with a two-stage countercurrent extraction process to produce a loaded organic phase, which was later stripped at the O/A ratio of two with a 4-M NaOH solution in a two-stage countercurrent stripping process using Taguchi?s optimization technique.

Jan 1, 2010

By Larissa Koroznikova, Steve Durkin, Bradley Drake, Michael Tuck

This paper presents the results from the investigation of the application of thermal fragmentation in Australian hard rock underground narrow-vein mining. Two geologically similar samples from an underground narrow-vein hard rock gold mine were collected to obtain a measure of the technology’s ability to recover ore by the creation of large thermal openings to assess the applicability of the thermal method. Particle size distribution showed a higher generation of fine product, − 2 mm, by thermal fragmentation compared with selective blasting by 31%. The Bond work index for thermal ore (12.62 kWh/t) is half to that of the blasted ore value (25.32 kWh/t). The average grindability obtained for the thermal ore sample was greater than the blasted sample by a factor of 2.44, a higher value indicating a decrease in the energy required to grind. The thermal fragmentation method generates product with higher dissolution of gold in cyanide, by 14% for the − 9.5 + 2 mm size fraction samples. Additionally, the thermal fragmentation results in higher production of − 9.5 + 2 mm material by 15 % compared with selective blasting.

By Larissa Koroznikova, Steve Durkin, Bradley Drake, Michael Tuck

This paper presents the results from the investigation of the application of thermal fragmentation in Australian hard rock underground narrow-vein mining. Two geologically similar samples from an underground narrow-vein hard rock gold mine were collected to obtain a measure of the technology’s ability to recover ore by the creation of large thermal openings to assess the applicability of the thermal method. Particle size distribution showed a higher generation of fine product, − 2 mm, by thermal fragmentation compared with selective blasting by 31%. The Bond work index for thermal ore (12.62 kWh/t) is half to that of the blasted ore value (25.32 kWh/t). The average grindability obtained for the thermal ore sample was greater than the blasted sample by a factor of 2.44, a higher value indicating a decrease in the energy required to grind. The thermal fragmentation method generates product with higher dissolution of gold in cyanide, by 14% for the − 9.5 + 2 mm size fraction samples. Additionally, the thermal fragmentation results in higher production of − 9.5 + 2 mm material by 15 % compared with selective blasting.

By Larissa Koroznikova, Steve Durkin, Bradley Drake, Michael Tuck

This paper presents the results of an investigation of the application of thermal fragmentation in Australian hard-rock, underground, narrow-vein mining. Two geologically similar samples from an underground, narrow-vein, hard-rock gold mine were collected to obtain a measure of the technology’s ability to recover ore by the creation of large thermal openings to assess the applicability of the thermal method.

Thermal pretreatment can significantly improve industrial comminution operations by reducing energy requirements and increasing mineral liberation. The effect of pretreatment using conventional and dielectric heating followed by quenching on the fracture properties of a number single and multiphase brittle materials has been investigated. The reduction in the impact fracture energies and particle strengths with and without pretreatment has been measured in precise single-particle experiments using the Ultrafast Load Cell. Variations in the fragmentation pattern caused by different pretreatments were assessed by measurements of the progeny size distributions. The differences in the effect of thermal treatment on single and multiphase materials are discussed based on the experimental results.

Jan 1, 1995

By William M. Turner

Thermonics is a methodology of ground-water flow system analysis based upon the distribution of heat within the subsurface as influenced by moving ground water. Thermonics is based upon the Stallman Equation 1 (1) which describes the simultaneous transfer of heat through a porous medium which contains moving ground water. The Stallman Equation is:

Jan 1, 1980

By Liyan Ren, Huayang Dai, Yingcheng Li, Enquan Wang

"Three-dimensional geological modelling of coal mines is critical to the sustainable development of the mining industry. On the basis of comprehensively analyzing 3D geological modelling methods, according to the available data of mine such as geological terrain maps, cross-sections and boreholes, we present a 3D modelling method by integrating ArcGIS and 3D GeoModeller. Our motivation is to integrate the advantages of both software modules in processing, converting, integrating and transferring geological information. Special attention has been given to the data structure and processing flow. We build a 3D geological model of the Xieqiao coal mine and successfully extract the geological framework of the strata in the 11118 workface, which is consistent with that of the actual explored geology.Introduction/Background Pertinent impediments such as a lower information degree, the out-of-date information infrastructure and the low level of information management and decision-making make it critical for there to be improvements in mines. Modern exploration technologies favour the construction of digital mine. Digital mine promotes the transformation of the mining industry by integrating information, automation and intelligence to build safe, efficient, high-yield, green and sustainable mines. Three-dimensional geological modelling and visualization of mines are at the core of digital mine. Compared with traditional 2D geological data, 3D models express the various geological phenomena completely, as well as reproduce the spatial distribution of geological units quickly, allowing for the prediction of mining subsidence, better decision-making and improved geological analysis. Modelling methods such as multi-DEM, tetrahedral grid and the generalized tri-prism that are based on borehole estimation and interpolation data are used to construct 3D models of mine geology (Chen 1995,Wang et al 2003, Wu 2004a); nevertheless, these methods cannot fully use multi-source mining data, whereas multi-source integration methods can be used to build 3D models (Kaufmann and Martin 2008, Zhao et al 2009) but require user interaction in model construction and low automation in model updates. During coal production, a plethora of geological data is accumulated. The organisation of discreteinformation under dynamic conditions and the extraction of meaningful information to better service for three-dimensional modelling is a meaningful work (Wu et al 2004b)."

Jan 1, 2017

By D. W. Park

Longwall mining is popular in underground coal production in the United States due to higher production rates and safety concerns. Because of the extreme complexity, it is necessary to plan an adequate design to achieve a safe and efficient working place. The proper sizes of yield and abutment pillars and panels can be determined by simulation using numerical modeling techniques. By means of three-dimensional modeling, stresses to be imposed on the pillars, panels, gob, and powered supports can be analyzed. In this study, an initial three-dimensional finite element model was developed and then modified into four different models. Using these models, the numerical outputs of distributed stresses on three different sizes of yield pillars, three different sizes of panels, and two different sizes of abutment pillars were compared and analyzed to determine the most adequate pillar and panel sizes. Progressive failure theory based on the Hoek and Brown failure criterion was used to determine redistribution of stresses in the yielded and failed areas in the longwall mine.

Jan 1, 1992

By R. D. Hammett

This paper describes an investigation that MS carried out using the three-dimensional, stress analysis computer program "NFOLD" to assess pillar stability in relation to existing mining conditions and the proposed layout of future stopes. The stress analyses were designed to assess the present stability of the mine (particularly the pillars adjacent to the shaft), the change in pillar stresses as mining proceeds, and the optimum stope geometry to minimize ground control problems. The existing conditions were modelled first, and rock mass strengths were adjusted until a good agreement between the predicted and observed conditions was obtained. Analyses of alternative mining layouts, based on the calibrated rock mass strengths, were then compared. The paper describes the results and the conclusions of the study.

Jan 1, 1983

In underground coal mining, one of the biggest challenges is spontaneous combustion, which will not only present safety hazards but result in reserve losses as a result of burnt coal. The released heat coupled with other combustible gases commonly encountered underground will significantly increase the risk of explosion. In this paper, three-phase foam as an environment-friendly fire fighting agent composed of nitrogen, water and fly ash is introduced. The nitrogen facilitates inertization of the fire zone; the water helps cool down the fire and the fly ash can closely cover the coal to isolate the oxygen. What's more, the fly ash and the foaming agent are good free radical absorption. The comprehensive merits mentioned above make three-phase foam quite effective in quenching spontaneous combustion. Experiments indicate that three-phase foam can significantly slow down the temperature rise of coal during oxidation. The comparison between slurry and three-phase foam shows that the latter one is capable of flowing upward in the porous media so as to extinguish the high-point fire and concealed fire.

Jan 1, 2011

By Thomas J. Crocker, Douglas B. Uthus

Tunnel Boring Machines (TBM) have gained worldwide acceptance in the construction field and are being employed in ever increasing numbers to drive underground transit lines, drainage systems, etc. However, TBM utilization in the mining industry, and more specifically coal mining, has been very limited. This paper reviews past and present applications of TBMs to coal mining and examines the needs of the industry in an attempt to offer some insight as to what a TBM system must provide if the excavation potential demonstrated in civil works projects is to be realized in coal operations. EUROPEAN EXPERIENCE Germany The Germans recognized long ago the potential of mechanized drivage for coal mine entry development. Early in the 1960's experimental runs were made with a full-face Wohlmyer roadheader at the Westerholt Mine and trials were conducted on a roller bit armed full-face Bade roadheader. But because of problems with penetrating the various carboniferous strata occurring in changing sequence and hardness, these first attempts were soon terminated. After viewing later successes in the construction industry with improved TBMs, new attempts were initiated by the German mining industry in 1971 to mechanize drivage of their development entries. Four TBMs of two different types were placed in operation.

Jan 1, 1976

By J. Franko, M. S. Klima

Wet-drum magnetic separators are used extensively for upgrading iron ore and for magnetite recovery in dense-medium separation circuits. In this study, the performance of a continuous, laboratory wet-drum magnetic separator was evaluated both with and without the application of ultrasonic energy when processing dense medium slurries. Test variables included magnetic-to-nonmagnetic ratio, solids concentration and nonmagnetic material. The results indicate that, under certain conditions, the purity of the magnetic material increased after ultrasonic treatment. Key words: Ultrasonics, Wet-drum magnetic separation, Iron ore

Jan 1, 2003

By L. Franko, S. Klima

Wet-drum magnetic separators are used extensively for upgrading iron ore and for magnetite recovery in dense-medium circuits. In this study the performance of a continuous, laboratory wet-drum magnetic separator was evaluated with and without the application of ultrasonic energy when processing dense medium slurries. Test variables included magnetic-to-nonmagnetic ratio, solids concentration, and nonmagnetic materials. The results indicate that under certain conditions, the purity of the magnetic material increased after ultrasonic treatment.

Jan 1, 2001

By N. Akbulut, A. Anani

From the initial planning phases to the closing of a mine, mining is an industry where high attention, care, and sensitivity are needed in every step of the mine life. Since mining projects have a long-life span, exceeding a decade sometimes, managing a whole mine project is challenging, especially when challenges faced due to generational differences are considered, such as tracking and logging data, or the usage of different engineering solutions change over time. Along with the overall hardship caused by the time put into a mining project, the present-time operations are very costly where each minute counts. In present-time operations, every decision made, and every minute used during planning and operations has an impact on the efficiency, safety, and economics of the project. Having extremely harsh conditions in both the excavation and mineral processing operations not only slows down the processes but creates very dangerous environments that need to be handled with precise safety measurements. To support the already established processes, we could implement new technologies and use them to our advantage. Virtual reality (VR) is one of these technologies that we could implement in the mining industry. VR is a technology that emerged in the 1960s creating virtual environments and platforms. The user experiences these virtual environments from head- mounted headsets to rooms with 360 screens, all with different levels of immersion. These higher levels of immersion, create a higher level of presencemaking the users more engaged in the activity they are trying to accomplish. These two factors of immersion and presence are what make VR unique and beneficial. VR has some applications and case studies in the industry along with some research being conducted in universities. Unfortunately, there has not been a comprehensive literature review or analysis regarding only VR and its implementations for the mining industry in the last 5 years. This paper aims to describe what VR is and its relation to the mining industry, in the most recent years. The paper first gives a brief background on what VR is and its key concepts. Secondly, it will give information on how the initial stages of the literature review were conducted and the findings along with discussions. The paper will finish with the conclusion drawn from the discussion and potential future work.

Feb 1, 2023