Design Of Full-scale Plant Research Articles

Tailings Filtration Using Viper Filtration Technology\u2014a Case Study

Investigation and uptake of filtered tailings continues to grow throughout the globe. This is driven by a wide range of site-specific considerations, which include such factors as tailings characteristics (e.g., amenability to filtration), production rates, climate, water availability, cost drivers, environmental requirements, and social factors. Despite the aforementioned technological growth, the currently available filtration technology is not able to meet the needs of many operations and projects that would otherwise adopt the technology. Experience with large-scale industrial filtration shows that vacuum belt filter systems meet the needs of many modern users, exceptions being the inability to effectively dewater tailings at altitude and/or with a fine particle size distribution: a potential fatal flaw. This paper presents a case study on the utilization of the patented Viper Filtration technology on gold tailings to overcome this challenge and shares the resultant full-scale plant design, highlighting the features designed to overcome cost and scalability deterrents. This technology is a novel mechanical process which complements the vacuum pressure in dewatering the filter cake as it travels along the belt filter. This project commenced with a pilot testing program, which successfully met the objective to rigorously test, measure and record any performance improvements achieved when engaging the Viper technology. Of the two tailings products tested, gross improvements of 4.2%w/w and 5.7%w/w were achieved when compared to the conventional vacuum belt filter operation. This pilot testing facilitated measurement of operating and design data, which forms the basis of the full-scale system design and resultant equipment supply of three vibration roller assemblies for retro-fitting on the existing vacuum belt filter.

PILOT -SCALE, HIGH-STRENGTH INDUSTRIAL WASTEWATER TREATMENT EVALUATION BY MATHEMATICAL MODELLING

An existing rendering plant wastewater treatment facility has to be upgraded to meet the newly set British and more stringent EC effluent standards. After detailed analysis it turned out, that the existing treatment plant cannot be upgraded, a new plant has to be built. The rendering plant processes slaughterhouse wastes. The wastewater contains easily biodegradable organic substances, mainly organic acids, organic bonded nitrogen and ammonia. According to the new effluent standards the main task, besides the organic removal was the complete removal of nitrogen. The aim of this study was to find out the best available technology and the basic wastewater design data. For this purpose, on site pilot scale experiments were carried out. In several test runs the influent BOD and T K N have varied of between 1400-5500 and 460-1120 mg/l, respectively. Based on the experimental results, single-sludge nitrification-denitrification technology was selected for the full scale treatment plant. The plant was extended by chemical phosphate removal applying the post-precipitation method. In addition to the experimental schedule, a mathematical model of the plant was developed for two purposes.– to verify the applicability of the general activated sludge model under high concentration influent conditions, and– to generalize experimental results and provide a tool to predict plant performance under full scale conditions. On the basis of successful pilot plant experiments and model calibration, full scale plant design parameters were determined and presented. The full scale plant is under construction.

Biological Treatment for Low-Activity Nuclear Wastewaters

Safety problems loom so large for the nuclear industry that provision must always be made in treatment of liquid wastes for their recycling to the production process. In this regard, a wastewater treatment consisting mainly of ammonia stripping, biological denitrification and chemical precipitation, looks very promising. With reference to the biological stage, this paper sets out the results of bench-scale tests performed to evaluate dimensioning parameters for the denitrification process. The tetrahydrofurfury1 alcohol, the major organic compound in the wastewater, was used as electron-donor substance. The procedure adopted for full-scale plant design and the preliminary results obtained using it, are also presented.

An Integrated Low Cost System for Treatment of Potato Processing Wastewater Incorporating Anaerobic Fermentation and Phosphorus Removal

The pollution load from a modern potato processing plant represents a substantial wastewater treatment and disposal problem with considerable potential for process innovation. With continued increase in energy costs, recent developments in treatment of industrial organic wastes by direct anaerobic fermentation rather than conventional energy intensive aerobic processes, offer considerable cost savings for wastewater treatment in the potato and other food processing industries. The development, through pilot plant investigations, of a low cost, integrated system incorporating anaerobic fermentation and phosphorus removal facilities is described. Details of full scale plant design, performance and costs, including aspects of utilization of treatment plant by-product biogas, and land disposal of residual phosphorus sludge as low grade fertilizer, are presented. Operating data obtained since commissioning of the full scale plant in January, 1980 demonstrates consistent achievement of an overall B.O.D.5 removal efficiency of 90% and an overall phosphorus removal efficiency of 93%. Total annual treatment cost is $A0.15/kg B0D5 removed (1981 costs).

The Thermosludge Water Treating and Steam Generation Process

Abstract The Thermosludge process internally softens and makes high-pressure steam directly from hard and saline oilfield or other water. Pilot plant and early full-scale plant work established several physical and chemical principles found necessary or desirable for good operation, and for control and practical elimination of scale on the process heating surfaces. These principles are use of a secondary liquid heat transfer medium, provision of time and space for water chemical reactions ahead of the boiling zone, and presence of sludged reaction products throughout the boiling zone. Other pertinent factors are discussed such as dissolved and suspended solids limits, foaming, corrosion, and heat transfer. Introduction In 1964 considerable use of steam in California oil fields was beginning to cause shortages of good steam generator feedwater in some areas. It seemed evident that in some situations oilfield brine or other low-quality water would have to be used to generate high-pressure steam directly. The Thermosludge process was developed to meet this need, and early results of its field use have been reported previously. This article discusses both pilot plant and full-scale plant design and operation particularly relative to the high-temperature reactions and scaling characteristics of some of the chemicals present in the waters. Present understanding of the process should allow broader use in its original field, and in other processing areas dealing with difficult waters. Pilot Plant Design and Operation After considerable study of chemical and engineering factors involved, a pilot plant program was set up. Three main theories or principles believed to lead to successful operation were followed in the pilot plant design and the same principles were carried into the full-scale plant design. First, heat should be applied via a secondary fluid heat transfer medium rather than directly in a combustion space. Relative to direct-fired beating, the secondary fluid heating guarantees that maximum tube wall temperature will be well within the allowable metal temperature limit regardless of local scaling or salting up. Many situations call for soluble salt in the steam generator in concentrations of as much as 15 percent by weight perhaps half of the limiting solubility. Even if conventional tube scaling were somehow entirely prevented, such situations would require the inherent heat flux control of a secondary heat medium to prevent gross fouling and plugging by salt deposits. Second, means should be provided in terms of high-temperature time and volume to preheat and chemically react the feedwater before it enters the boiling zone. The practicality of this is based on the expectation that thermally induced mineral sludging reactions will proceed much faster and more completely in the 350 to 600F environment than, for example, in the conventional lime-soda process. Thus, the feedwater should be entirely softened by the time it arrives at the boiling zone.