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By Brian Gettinger, Jared Barber, Richard Weatherly, Shannon Dunne, Jeff Masek, Chuck Wolf, Fazle Rabbi, Jack Canfield

During Hurricane Harvey over 60% of the 39 WWTPs, including the low-lying 25 MGD Sims North WWTP, and one third of the 382 lift stations owned and operated by the City of Houston were flooded resulting in extensive facility damage, loss of service and uncontrolled release of untreated wastewater into bayous and creeks. In response, the City has embarked on an effort to improve system resiliency by consolidating at-risk facilities with a network of deep sewer tunnels. These tunnels will provide secondary benefits to the collection system of augmenting the capacity of the existing 6,000 miles of sewer mains and lowering the collection system profile in poor performing areas. Investigations on the cost to mitigate the flood damages by raising the liquid stream processes at the Sims North WWTP is estimated at nearly $450 million. Instead of spending $450 million to raise the plant, the funds will be directed to providing a more robust and resilient wastewater system for the Sims basin area of Houston. The backbone of this new system is a 4.5-mile-long, 110 inch diameter deep gravity sewer tunnel that will convert a system heavily reliant on distributed lift stations to a majority gravity system with a deep consolidated lift station at the Sims South WWTP. This will also allow the City to address the flood prone infrastructure at Sims North and consolidate its operations into a single permitted outfall for this collection system. This approach is the outcome of a team effort focused on maximizing system resiliency and sustainability for the next 100 years. By thinking outside the box, the City of Houston will not only mitigate the flooding risk at Sims North WWTP, but also solve regulatory and operational challenges throughout the sewershed and deliver a winwin on multiple levels.

Jun 13, 2021

By Steve Axen

In situ mining is now considered an alternative mining method for some ore bodies. The in situ operation consists of a well field designed from reservoir properties and geological information; the wells for such a field are then drilled, cased, and cemented, using good designs and practices to eliminate future problems. Injection and production (recovery) systems are required to be corrosion resistant. Hand in hand with the mining operation is the metal extraction plant, the entire operation offering an environmentally acceptable method for metal recovery. Great opportunity exists in this field for mineral engineers; presently, they must borrow knowledge from other fields, since the schools have not yet addressed this specialty.

Jan 1, 1979

By David G. Chedgy

The Meadow River No. 1 Preparation Plant, owned by Sewell Coal Company, a subsidiary of the Pittston Company, was commissioned in the spring of 1974. The plant is designed to process 400 TPH of 5" x 0 raw coal. The 5" x 114'l fraction is processed in a Heavy Medium Vessel with the 114 x 28M reporting to Deister Tables for cleaning. The 28M x 0 fraction is cleaned in flotation cells, with the froth going to clean coal vacuum filters and the tailings to a static thickener where the underflow is reclaimed on Refuse Filters prior to disposal. The noise dosage a worker receives is determined by the ratio of the length of time the worker spends in a particular noise environment divided by the noise exposure in that particular environment. If the worker is exposed to several different sound levels, his total dosage would be the sum of each of the individual dosages. The equation for determining the dosage is: [ ]

Jan 1, 1976

By S. L. Barua

An industrial engineering and computer simulation study was conducted on reclamation operations to evaluate the possibility of integrating mining and reclamation operations, and to evaluate the factors which influence the production potential of scrapers. The study was done in a southern Illinois strip coal mine producing approximately 2.27 M metric tons (2.5 million short tons) of clean coal annually. The main outcomes of this study are (a) it is possible to reduce reclamation cost about 20-25 percent by integrating reclamation and mining operations, (b) haul distance has the most significant effect on scraper production, (c) push-pull is the best mode of operation for wheel scrapers for topsoil/subsoil removal, and (d) historical data obtained from the mine for one year show that average dozer productivity in rock grading is about 60 percent lower than the expected production; similar data for scraper is about 25 percent less.

Jan 1, 1981

By Tom L. Enos

Increased production through the plant was limited due to thickener circuit constraints. To overcome these constraints and maximize plant throughput to match grinding circuit capability, two options were considered: A. Adding 2000 TPD CIL circuit to operate in parallel with the existing CCD circuit. B. Adding a CIL circuit to treat the entire 4600 TPD while retaining some thickeners for tailings thickening. Option B was selected based on simplified plant operations, reduced operating costs, minimal capital requirements, reduced solution losses, and bullion grade improvement.

Jan 1, 1989

The structure of a mine ventilation network (M.V.N.) can be represented graphically using either the mine plan (map) itself or a number of other types of diagrams. In the U.S., the two most common approaches are the line and the schematic diagrams (see Figures 1 and 2). The purpose of this paper is to introduce another type of diagram, called the canonical diagram (6). The method of M.V.N. representation which uses canonical diagrams is used extensively in Europe, and especially in Poland, where it was developed. The canonical diagram is a noncalibrated topological image of a ventilation system. It gives a simple representation of the ventilation network, allows for the classification of currents within it and enables rapid computer analysis and computation, as well as the representation of the results. It is especially useful in studying and controlling the air flow, and it may be a life saving tool in conducting rescue operations during and after mine fires.

Jan 1, 1986

By Daniel Threlfall

The disposal of hazardous chemical wastes will be one of the major environmental issues of the 1980's. Approximately 50 million tons of hazardous wastes are produced yearly. One of the major aspects of the problem is the siting, design and construction of environmentally acceptable disposal facilities to accommodate this huge volume of material. Surface mines have been considered attractive for development as disposal sires for several reasons: 1. Surface mines represent an open pit that can conveniently serve as a repository for wastes. This could represent a significant economic savings when compared with sites on undisturbed lands chat might require extensive excavation or embankment construction.

Jan 1, 1981

By BERND SCHÖNHERR, JÖRG DEHNERT, PETER WINDISCH, JENS STOPP

The Quick-Erect Stopping System (QESS) offers a new way of reducing the radon exposure of miners in Germany, especially during remediation work in old mines. The QESS is a lightweight, modular and reusable construction kit of interlocking telescopic aluminum tubes, radon-proof foil and expanding foam. It is designed to seal off radon-rich parts of galleries within minutes. Originally, the QESS was developed to protect miners against radon exposure. Then, the QESS found the attention of several mine rescue teams at a German mining conference. Some mine rescue drills by The Student Mine Rescue of the Technical University Bergakademie Freiberg, Wismut Mine Rescue and Front Range Mine Rescue helped to improve the system and highlighted its potential for mine rescue operations. Now, the QESS is well-suited for small-scale mining. The QESS can be used to both protect miners from radon exposure and to support mine rescue operations. Moreover, the QESS was also successfully used in ventilation experiments.

By T. Y. Yan

The various ion exchange reactions occurring during the restoration of formations contaminated with ammonia during in situ uranium leaching are reviewed. Data are presented on the restoration of a previously leached laboratory packed column using line saturated brine. Although this restoration fluid selectively and effectively removed the ammonia, 24.5 pore volumes are required to reduce the ammonia concentration from 500 to 3 ppm. The presence of NaCl in the restoration fluid is beneficial in + improving the selectivity of the system for NH removal and reducing ca++ ion consumption.

Jan 1, 1982

By John W. Stevenson

At the No. 4 Mine of Jim Walter Resources in Tuscaloosa County in the North Central part of the State of Alabama, the Mary Lee and Blue Creek coal beds lay 2000 feet below the surface. The quantity of methane gas stored within the coal bed reservoir at this depth and released during development mining necessitates that each coal producing section be ventilated using large air quantities approaching 100,000 cfm. In order to meet coal contractural commitments in the early stages of mine development by installing the necessary number of continuous mining machine units and to develop the mine to projected air shaft sites, high pressure, large volume mine ventilating fans were required. This presentation discusses the installation start-up and changeover procedures when two size GAF 31.5-28-1 TLT-Babcock 3500 Horsepower fans with adjustable pitch in flight blades were put on line while phasing out two Jeffrey Mining Machine Company 8HUA 117 Fans. A graph will be presented to depict the most economic diameter shaft size under 2000 feet of cover with different air quantity requirements.

Jan 1, 1982

By Peter Dietrich, Joseph DeMello, Norbert Fuegenschuh, Kerwin Hirro, Jeff Brandt, Mike Cole

This paper presents a successful case history of the ground improvement efforts and excavation of twenty-three cross passages between twin bore tunnels driven by EPB tunneling machines in Los Angeles, California on Section 1 of the Westside Subway Extension. Unique and complicated ground conditions local to the tunnel alignment include San Pedro sands, siltstone/claystone Fernando Formation, and zones of “asphalt impacted soils.” To provide water cut-off and soil stabilization, jet grouting was performed prior to TBM excavation at the location of many of the cross passages. However, upon investigating the cross passages prior to excavation, the subsurface conditions required additional measures and SEM tools to ensure successful completion of the project.

Jun 13, 2023

By Richard Klimpel

The influence of selective chemical dispersants on the hydrocycloning of a copper ore slurry is illustrated. In the % solids and slurry feed rate ranges associated with industrial practice, desirable changes in both d50 and Sharpness Index values of classification were measured with the use of chemical as compared to tests with no chemical usage.

Jan 1, 1981

By Xiaolong Bi, Shaohua Luo, Longjiao Chang, Shiyuan Cao, Jianan Liu

The abstract discusses the extraction of silica from nickel laterite ore using a hydrothermal process with sodium hydroxide. The effects of reaction temperature, time, and NaOH-to-ore ratio on silica extraction were investigated. The optimal conditions were determined, achieving over 98% silica extraction. The mechanism involves the reaction of Si in lizardite and quartz with sodium hydroxide, forming sodium silicate solution. Other metals like Mg, Fe, and Ni are enriched in the residue.

Apr 21, 2022

By Poltak Sinaga

PT Kaltim Prima Coal's 13.1 km overland conveyor was commissioned in 1991. It is of conventional 3 roller 350 troughed belt type. Cost and performance optimisation during initial design ended up with 5.4m/s belt speed, 1,000mm belt width to convey 1,350tph, and 7mtpa of coal. Despite high initial figure, the belt speed was lifted to 6.5 mps in 1996 to accommodate mine throughput increase. In 2002, new low loss ST2100 1,100mm wide belt replaced the old ST2250 due for change-out. An upgrade project was initiated at the end of 2003 to further increase the belt speed to 8.5 mps, hence to increase the OLC capacity to 30mtpa. Performance data, experience of site personnel, site observation and tests, benchmarking, and information from equipment manufacturers were major inputs to the design review. The project fast track was another challenge in addition to executing modifications on a production lifeline. The project was completed within fifteen months and the OLC was successfully commissioned at 8.5 mps belt speed in February 2005. The OLC has been to date conveying 4200tph satisfactorily.

Jan 1, 2008

By N. Sloan Dworian, Alyssa Smith, Ian Kellogg

Many studies have utilized magnetic susceptibility data to fingerprint porphyry copper centers; however, usage of magnetic susceptibility data to identify trends in a Climaxtype molybdenum porphyry deposit is limited. To better understand potential petrophysical signatures in a Climaxtype Mo porphyry deposit, magnetic susceptibility data was gathered at regular intervals from core holes across the Climax Mine, targeting major lithologies and styles of alteration. Preliminary analysis suggests that there are quantifiable patterns which may correspond with the mineralizing intrusions. This data can complement current mapping and exploration techniques to identify Climax-type molybdenum porphyry centers and likewise further the exploration potential for this deposit type.

Feb 22, 2026

By William J. Robinson

What is the cummulative rate of recovery of copper from a sulfide leach dump? This is one of the most frequently asked questions today. We, in the industry, ask it of each other when we meet; however, the technical answers may vary from "I don't know" to 'quite good" from people within the same company. Management also poses this question because it plays a vital role in our planning for future production. The answer is difficult because of the many variables between different operations such as physical construction of the dump, topography of the original site, characteristics of dump material, mineralization, water application, etc. Each has a bearing on the rate of recovery. OPERATIONAL DATA Our method of water distribution is unique in that each dump is drilled to allow physical injection of water into the dump. The in¬jection holes are drilled vertically, on 251 centers, from the surface of the dump. Normally, the holes are drilled 40' deep and cased with 4" PVC perforated pipe.. The pipe is perforated at one-foot intervals with four V diameter holes at 901 spacing on the pipe circumference. We formerly alternated shallow holes (20'-40') with deep holes (80'-l80') in an effort to cover the entire dump and hasten oxidation. The shallow hole depth varied according to the compaction thickness. The deep hole depth varied according to the height of the dump and the original ground profile, We prefer to have the deep holes end 20'-30' above the original ground level. This generally allows us to penetrate the coarse material at the bottom of the dump. We had to discontinue the deep holes_ in order to cover more dump area in a shorter period of time to meet increased production requirements.

Jan 1, 1972

By William Gleason

With more than 20 major mines extracting copper, gold, coal, molybdenum and lime, Arizona is recognized as one of the better mining jurisdictions, not just in the United States, but in the world. However, that is not to say the road to production is always paved with gold, or in many cases, copper. Earning the license to mine in Arizona is a complex process with years of paperwork and permitting before the first tons of ore are ever processed. Now, get the federal government involved and the process becomes even more complex, and the path to production can become even longer.

Jan 1, 2013

By R. Gray, B. Hebblewhite

Experience from Australia had identified what is referred to as nonconventional surface subsidence behavior. This occurs under irregular surface topography, resulting in valley closure, valley floor uplift or “upsidence,” and far-field horizontal movements, occurring even beyond conventional “angle of draw” limits. This paper discusses such behavior recently observed in Pennsylvania and focuses on the 2005 case of Duke Lake Dam in Ryerson Station State Park. In July 2005, there was a significant increase in water leakage through a number of growing cracks in the dam, leading to the dam being breached to avoid an uncontrolled failure. An underground longwall mine was located approximately 900 ft to the north, mining at depths of 330 to 720 ft. Investigations, including a subsequent ground movement monitoring program, found a range of evidence in the vicinity suggesting that valley closure and farfield horizontal movements may have occurred, resulting from the adjacent mining. Besides discussing the phenomenon of nonconventional subsidence behavior and the Ryerson State Park case study, this paper includes an assessment of the mining, geology and subsidence impacts and suggested ground behavioral mechanisms.

Jan 1, 2015

By R. Miller

Lowering our globe’s emissions is a major effort as we move toward a future net-zero carbon environment requiring significant investment in a new, low-carbon infrastructure, along with key market incentives to change. Industry will play a key part in this transformation, requiring expertise in both energy and emissions. Key elements of the de-carbonization strategy are: energy data, emissions reporting method, governance, de-carbonization project generation and drivers, the MACC, electrification, and the de-carbonization checklist. For a zero carbon future, it will be key for business leaders to understand decarbonization, anticipate technological changes, and implement new business me

Mar 2, 2022

By J. H. Kelley

In this paper, we show that the methane emission and the dust generation in under-ground mining currently and in the future pose operational, health and safety conditions which adversely Impact face productivity and worker satisfaction. One solution is the use of a dual-aircourse system of ventilation. In this concept, one aircourse captures and exhausts to the surface the dust generated and the methane emitted in coal/mineral fragmentation while a second aircourse provides workers with cleaner air for breathing and comfort. Various dual-aircourse configurations adapted to the Variable Wall Miner are analyzed and compared with conventional mining in gassy seams, indicating a marked reduction in the required air quantity and the number of aircourses.

Jan 1, 1996