Jozef Szymanski

A novel process for recovering clean coal and water from coal tailings

Recovery of fine coals from coal preparation tailings and recycle of processing water are of both economic and environmental incentives, not only preserving natural resources but also reducing environmental consequences of discharging large volume of tailings. A novel single stage process capable of recovering fine coals in liquid fuels and clarifying water for recycle is described. This process integrates three distinct mechanisms: hydrophobic extraction, electrolytic coagulation, and macromolecular flocculation. Using this process, a combustible recovery greater than 88% at an ash content less than 11% was obtained while producing a clean water containing less than 20 ppm suspended solids from a tailings stream. The final product of coal-in-oil mixture can be a potential fuel suitable for coal-firing boilers and power generators.

Intelligent Modeling: Advances in Open Pit Mine Design and Optimization Research

Design and optimization of pit layouts yield the mineable ore reserves and minimum waste to maximize the net pit value and to ensure optimum location of surface facilities. Many algorithms and their modifications, derived from stripping ratio concepts, displacement of conic volumes, dynamic programming and graph theory, have been developed to design and optimize pit layouts. These algorithms have assisted engineers in making design decisions but they are limited in dealing with pit design stochastic processes. Large information and database and the requirement for complete rerun of these algorithms with information and data changes result in long computations and CPU times. Current algorithms do not provide analysts with intelligent design options to deal with structural, hydrological and tectonics problems of mine design. In this paper, the authors discuss current state-of-the-art technology and research in intelligent modeling. Current and future research frontiers in intelligent modeling are also addressed with emphasis on developing efficient and user-friendly technology for pit design and optimization.

Spatial Modeling of Geometallurgical Properties: Techniques and a Case Study

High-resolution spatial numerical models of metallurgical properties constrained by geological controls and more extensively by measured grade and geomechanical properties constitute an important part of geometallurgy. Geostatistical and other numerical techniques are adapted and developed to construct these high-resolution models accounting for all available data. Important issues that must be addressed include unequal sampling of the metallurgical properties versus grade assays, measurements at different scale, and complex nonlinear averaging of many metallurgical parameters. This paper establishes techniques to address each of these issues with the required implementation details and also demonstrates geometallurgical mineral deposit characterization for a copper–molybdenum deposit in South America. High-resolution models of grades and comminution indices are constructed, checked, and are rigorously validated. The workflow demonstrated in this case study is applicable to many other deposit types.

Modelling Open Pit Dynamics Using Discrete Simulation

The objective in any mining operation is to exploit ore at the lowest possible cost with the prospect of maximizing profits. The planning of an open pit mine is an economic exercise, constrained by certain geological, operating, technological and local field factors. Heuristic methods, economic parametric analysis, operations research and genetic algorithms have been used to formulate periodic open pit planning problems. Open pit design, optimization and subsequent materials scheduling problems are governed by stochastic dynamic process. Thus, current algorithms are limited in their abilities to address problems arising from these random and dynamic field processes. The primary objective of this study is to use a discrete stochastic simulation to capture the random field processes associated with open pit design and materials scheduling. An open pit production simulator (OPPS), implemented in MATLAB, based on a modified elliptical frustum is used to model the geometry of open pit layout expansion. The simulator mimics the periodic expansion of the open pit layouts. The interaction of the open pit expansion model with the geological and economic block model returns the respective amount of ore, waste, stockpile materials, and the net present value of the venture. A case study of an iron ore deposit with 114 000 blocks was carried out to verify and validate the model. The optimized pit limit was designed using the Lerchs – Grossman algorithm. The best-case annual schedule, generated by the shells node in Whittle Four-X, yielded a net present value (NPV) of

Hybrid Simulation for Oil-Solids-Water Separation in Oil Sands Production

414 million over a 21-year mine life at a discount rate of 10% per annum. The best scenario out of 5000 simulation iterations using OPPS resulted in an NPV of

Mechanics of Oil Sands Slurry Flow in a Flexible Pipeline System

422 million over the same time span. Further research, based on hybrid stochastic simulation in conjunction with reinforcement learning, can provide a powerful tool for addressing the random field and dynamic processes in long-term open pit planning.

Stochastic-Optimization Annealing of an Intelligent Open Pit Mine Design

Abstract Separation of oil-sand-water mixtures is vital in oil sands production and processing. The co-existence of sand and oil in oily water systems can cause corrosion problems to the operational facilities and equipment. Immoderate oil and oil-coated sand levels have negative impacts on the environment. This research attempts to provide further understanding and some solutions to this problem by hybridization of two hydrocyclones for solid-liquid and liquid-liquid separation. The hybrid hydrocyclone is hydrodynamically designed to incorporate a transverse aperture for sand rejection, a transformation of which enables concurrent liquid-solid-liquid three-phase separation of the oily sands. Through computer simulation, the hybrid hydrocyclone has demonstrated promising performance in separating oil-sand-water in a single-stage oil sands production operation. For concentration up to 40% by mass of feed there was good s stability and accuracy in the model determination. Beyond that, droplet degeneration and breakup and bedding, and bridging of the hybrid spigot by sand characterized poor accuracy. Two distinct phases of behaviour were exhibited in the hybrid model — collinear velocity spectra as the forced vortex flow emanated through a 5-mm radius cylindrical envelope co-axial with the hybrid and parabolic spectra as the flow proceeded beyond this transition envelope towards to its wall liberating the vortex.

Simulation of Automated Dump Trucks for Large Scale Surface Mining Operations

Slurry transportation is an economic haulage system in oil sands and coal-mining operations characterized by long haulage distances and rugged terrain. In such conditions, the ton-km-hr limits are exceeded creating extreme tire wear and high maintenance costs. Steep haul grades and rugged terrain also cause mechanical wear and tear, which decrease haulage equipment economic life. Hydraulic transportation is a proven and viable technology for slurry transportation in such conditions. Currently, stationary pipeline transportation is being used in transporting minerals in many mines. There is an increasing demand to create slurrified minerals at the mining faces to be transported to the processing plant. However, stationary pipelines are not capable for dealing with the rapidly changing configuration of the mining faces. In this paper, the authors develop the ground articulating pipeline (GAP) technology to address this problem. The GAP system consists of pipelines connected together with flexible joints in each pipe section, which allows deflection to avoid torsional stresses from the adjoining frames. This flexible arrangement accommodates the horizontal and vertical displacements of the mobile system as it follows the hydraulic shovels in the excavation process. The mechanics of the GAP system, as well as the production–economic function, are formulated and simulated over an extended period using data and information from Syncrude’s North Mine. The results show that the GAP system is technically and economically viable for productivity between 6,300 and 6,500 tons per hour. The simulated head loss for the GAP system is 15.66 m per 400 m, which compares with 20 m per 400 m for the existing stationary system at Syncrude. The pressure gradient-radius curves are asymptotic to the pipe boundaries, which indicates steep axial pressure gradient in these areas.

The northwest passage: a simulation

Optimized pit layouts are used to extract mineable reserves with minimum waste under geological, geotechnical and property boundary constraints and to develop strategic and tactical production plans for achieving corporate goals. Pit design and optimization algorithms are limited in dealing with the random field properties of these layouts resulting in sub-optimal results. Database changes require complete rerun of these algorithms resulting in long CPU times with no allowance for incorporating operating strategies. In this study, the authors develop an intelligent pit optimizer, IPOP, to solve these problems. It combines stochastic models of ore reserves and commodity prices to generate economic block and target values. The error backpropation algorithm is used to train the neural network for block pattern recognition and partitioning based on the target values. The PITSEARCH program is then used to search for the optimized layout under the pit slope constraints. Stochastic-optimization annealing is carried out to examine the random field properties of the optimized pit value. IPOP is used to optimize Section SBHP 860001 of the Sabi open pit in Zimbabwe, and the results are compared with that from the 2D Lerchs-Grossmanns algorithm. The two algorithms yield the same value of Z

Statistical Analysis of Coal Beneficiation Performance in a Continuous Air Dense Medium Fluidized Bed Separator

3.58 million for the optimized Section SBHP 860001. In addition, IPOP provides analysts with the risks associated with the optimized value of this section with a reduced CPU time.