Vertical Retort Research Articles

Increasing of the unit capacity of MF process at Miike Smelter

MF (Mitsui Furnace) is a half shaft blast furnace developed by Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. Currently MF mainly treats various secondary wastes (EAF dust, Secondary Fly Ash, etc.) and recovers zinc and lead as crude zinc oxide, copper and silver as matte, meanwhile other elements such as FeO, CaO, SiO2, Al2O3 are concentrated in slag.There are two steps in the MF process. The first step is pretreatment. In this process, various waste materials are blended in a certain proportion with reductant and dried adding binder in a rotary dryer, then grinded in a rod mill. The grinded materials are made into an oval briquette by briquetting machine. The second step is treatment process. The briquettes fed into the MF are smelted and reduced by blowing air through the tuyeres. By enriching the tuyere air with oxygen generated by the VSA (Vacuum Swing Adsorption) oxygen generator in 2005 and 2012, we have improved the throughput of wastes.By the improvement of oxygen enrichment in the MF, the unit capacity increased significantly. However shortage of the drying capacity in the pretreatment process became a problem. To ensure sufficient drying capacity, we installed one more rotary drier in series in 2016. Additionally in 2018, we installed a granulator after the rod mill to improve the bulk density in briquette. As a result of these efforts, the treatment amount in the whole MF process has increased.The MF can treat various kinds of materials containing various non-ferrous metal-valuables. Through these process improvements, we promote the treatment of wastes containing heavy metals and contributes significantly to the recycling of metal resources.

The effects of reductant and additive on the magnesium extraction from calcined dolomite via metallothermic reduction under vacuum condition

The extraction of magnesium from calcined dolomite via vacuum metallothermic reduction process has been evaluated thermodynamically and investigated experimentally. The equilibrium phases formed during the metallothermic reduction as a function of pressure, reductant, temperature, and additive combination were thermodynamically analyzed. The experimental work consisted of calcination of dolomite – (Ca,Mg)CO3 and metallothermic reduction of the calcined dolomite/dolime – (Ca,Mg)O. The metallothermic reductions of the dolime with different reductants and additives were carried out in a laboratory scale vertical retort at a final holding temperature of 1200 °C and pressure lower than 10−4 atm using different reductant types (ferrosilicon or aluminum) and different additive combinations (CaF2 and B2O3). Magnesium metal was extracted from the dolime through metallothermic reduction by either ferrosilicon or aluminum. The residue from reduction with ferrosilicon disintegrated into fine powder, while the residue from reduction with aluminum remained as briquette. The physical degradation of the residue from reduction with ferrosilicon was found to be minimized by the B2O3 addition. The CaF2 addition increased the magnesium extraction, while the B2O3 addition decreased the magnesium extraction.

Smelting of titanium-magnetite metallized pellets from the Tebinbulak deposit ore in submerged arc furnaces

Utilization of titanium-magnetite ores as complex raw materials aimed at extraction of iron and vanadium is an important and actual task. Technological capability of titanium-magnetite pellets application produced from the Tebinbulak deposit ore was studied for obtaining sponge iron and its further use in the production of liquid iron. Integrated theoretical and experimental studies of Tebinbulak deposit ore were carried out within the framework of the state program of the Republic of Uzbekistan by the company JSC “Uzbek Railways” (Republic of Uzbekistan, Tashkent) in cooperation with Horst Wiesinger Consulting (Austria, Linz) on the basis of the Research Center of the Leoben Mining University (MUL, Austria, Leoben), Studiengesellschaft für Eisenerzaufbereitung (SGA, Germany, Liebenburg-Othfresen) with the participation of the North Caucasus Mining and Metallurgical Institute (State Technological University) (Russia, Vladikavkaz). Experiments on direct solid-phase reduction of fired oxidized pellets have been implemented in a vertical retort in a hydrogen atmosphere at a temperature of 800 °C. As a result of the tests, the planned degree of metallization of the pellets was achieved, which averaged 93%. The obtained metallized pellets were melted in a 45 l volume furnace with a submerged electric arc. As a result of the tests, the target value of the carbon content in the liquid iron was achieved, which amounted for 4.3 – 4.6%. It was noted that according to the results of two heats, TiO 2 almost completely passed into the slag phase, where its average value was 3.55%.Average vanadium content of the liquid iron was 0.16%. During the studies it was found that at a chemically measured value from 0.71 to 0.73% V 2 O 5 in metallized pellets, the calculated theoretical maximum content of vanadium in liquid iron 0.49% can be achieved, providing all vanadium remains in the metal phase.

Halogen Derivatives in Pyrolyzed Plastics

The article deals with the issue of waste plastics pyrolysis leading to the industrially applicable liquid and gaseous products. The problem of thermally labile halogenated compounds, present in the feedstock, is discussed. The introductory part focuses mainly on halogenated flame retardants and their toxicological and environmental risks. In comparison with the standard recycling of waste plastics, pyrolysis with subsequent material utilization of the liquid product is mentioned as a promising method capable to solve the problem with the presence of halogen derivatives. The following second part of the article summarizes studies searching suitable methods for removing inorganically and organically bound chlorine and bromine from pyrolysis organic condensates - i.e. pyrolysis oils. Dehalogenation processes are divided into several categories according to the nature of the process and also according to the method of application of the respective reagent, catalyst or sorbent. Within each group, the results published in the available literature are briefly summarized. When commenting on them, the main emphasis is placed on the applicability of the obtained pyrolysis oils as raw materials for refinery processing and new polymers production. At the end of the article, a plan of experiments is outlined, which will be carried out during the research of the issue by the authors team. The space is mainly dedicated to the construction of two laboratory apparatuses that has been developed for this purpose.The first batch apparatus working with a vertical retort allows studying of gaseous, liquid and solid pyrolysis products at various temperatures. The second, continuously operating apparatus, is designed to test the efficiency of hydrogen halides adsorption from gaseous mix-tures at high temperatures. The third apparatus designed for the research purposes is a catalytic continuous system enabling to study the decomposition of organic halogen derivatives. The results of the experiments will be published continuously after their verification with sufficient reproducibility.

Venting stage experimental study of food sterilization process in a vertical retort using temperature distribution tests and energy balances

Thermal sterilization of canned food is widely used in the food preservation industry. This method ensures the microbiological safety of the products, helps to define their sensory properties, and preserves their nutrients. However, sterilization requires a significant amount of energy, which has an impact on the cost of the final product and the environment. In this paper, we present an experimental study into the energy balance in a vertical steam retort in a transient state during the venting stage with an initial product temperature of 4 °C and a container size of 63.5 × 30.16 mm. We carried out the experiments in accordance with the protocol for conducting temperature distribution studies developed by the Institute for Thermal Processing Specialists (IFTPS). Additionally, by means of a heuristic optimization method, we determined an optimal venting program for the process and its energy efficiency. The total energy consumption was 32.5 MJ; the thermal efficiency of the process, 43.88%; the losses through walls, drainage, venting, and purging, 27.82%; the energy required to heat the retort and the fittings, 22.91%; and others losses, 7.0%. Furthermore, we studied the phenomena associated with the sterilization process to propose strategies to reduce energy consumption.

Demystifying Food Safety Implementation by SMEs Using Innovative Cohort Factory Visits and 15Action-Oriented Steps to HACCP Certification

Ensuring food safety has been a major concern to small and medium-sized food manufacturers especially those in developing countries participating in international trade. In this connection, an action-oriented learning and factory visit by a cohort of 15 owners of food manufacturing SMEs to a world-class food factory in Ghana under the auspices of Partners in Food Solutions helped demystify HACCP implementation in the minds of these SME owners. This resulted in majority of them implementing HACCP within six months. A typical indigenous Ghanaian small and medium-sized enterprise (SME) engaged in palm cream concentrate canning was selected for HACCP study and the generic HACCP system was developed which is being adapted for the entire palm cream concentrate canning industry in West Africa. To manufacture canned palm cream concentrate, fresh and ripen palm fruits are harvested, weighed, inspected, and sorted for their quality. The quality palm fruits are washed, cooked at a temperature of 100°C for 30 min, depulped into paste, fiber and kernels. The paste with the fiber is squeezed and strained to obtain palm cream. The fine cream is collected and blended with 0.5% salt and heated to a temperature ≥ 70°C for 10 min. Empty cans are washed, filled with the hot cream, seamed, washed to get rid of stains and loaded into retort baskets and then hoisted into a vertical retort for sterilization. Retorting is done at 121°C for 60 minutes and then cooled to a temperature of 40°C and the product are removed from the retort and incubated at ambient temperature for 7 days. After which labelling is done and the product are cased and palletized ready for sale. The 14 stages of HACCP implementation including the 7 preparatory steps and the 7 principles of HACCP recommended by were applied in addition to 2 innovative steps to the palm cream concentrate canning process [1]. Each processing step was correctly captured in the process flow diagram and subjected to hazard analysis to identify all potential food safety hazards that are associated with each step. The identified hazards were classified as physical, chemical or biological and subjected to risk assessment process using a quantitative scoring method to determine the likelihood and severity of each potential hazard which helped to determine significant hazards with each step. The significant hazards were then subjected to critical control point determination using the codex decision tree. Three steps of microbiological significance were identified in the process as CCPs. These are can seam (CCP #1), retorting (CPP #2) and retorted can cooling (CCP #3). Critical limits were established for these limits as follows: CCP# 1 – can seaming (body hook butting (BHB) > 75%, thickness rating (TR) > 75% and actual overlap (AO) > 1.1mm), CCP# 2 – retorting (120 -122°C for 60 minutes at a pressure of 1bar must be achieved during sterilization) and CCP# 3 – can cooling (incoming cooling water into the retort must be chlorinated to 3 - 4 ppm, residual chlorine content and after cooling, the discharge water should contain ≥ 0.5ppm residual chlorine content). Monitoring and verification procedures were developed for each CCP and corrective actions and record keeping systems have been established for the CCPs.

ACHIEVING RESILIENCE AND SUSTAINABILITY THROUGH INNOVATIVE DESIGN FOR OIL SHALE PYROLYSIS PROCESS MODEL

Low international oil price, advance in renewable energy technology, development of energy storage technology and strict environmental regulations have presented encumbrance and opportunity for the current oil shale project development. Oil shale industry is at critical stage and facing challenges from competitive conventional energy, clean renewable energy and more strict environmental regulations. Through an innovative design of the oil shale pyrolysis process model by utilizing a developed new advanced technology, the oil shale project could improve its resilience and sustainability with excellent social and economic performance.This paper investigated the shale oil production process in terms of technology selection, utilization of resource, energy efficiency, oil yield, and mining to improve the resilience of oil shale project economic performance facing lower oil price. Innovative design options for the oil shale production process model were discussed from the following aspects: 1) itemized cost analysis and comparison of shale oil production technologies; 2) development of a new oil shale pyrolysis process model with combination of the existing vertical retort process (VRP) and horizontal rotary-kiln retort process (HRRP) technologies to improve the oil shale process economic gain; 3) discussion of innovative design options to improve the economic performance of the process by utilizing the current new advanced energy storage technology. Investigation of the applicability of the energy storage system (ESS) to the oil shale project was carried out with a sensitivity analysis of its cost-revenue.

Comprehensive database of Manufactured Gas Plant tars. Part A. Database.

Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. Different manufacturing processes have resulted in the production of distinctly different tar compositions. This study presents a comprehensive database of compounds produced using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS), analysing 16 tar samples produced by five distinct production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 16 tar samples originating from five different production processes: Low Temperature Horizontal Retorts, Horizontal Retorts, Vertical Retorts, Carbureted Water Gas and Coke Ovens, were analysed. A total of 2369 unique compounds were detected with 948 aromatic compounds, 196 aliphatic compounds, 380 sulfur-containing compounds, 209 oxygen-containing compounds, 262 nitrogen-containing compounds and 15 mixed heterocycles. Derivatisation allowed the detection of 359 unique compounds, the majority in the form of hydroxylated polycyclic aromatic hydrocarbons, many of which would not have been detected without derivatisation. Of the 2369 unique compounds detected, 173 were found to be present within all samples. A unique comprehensive database of compounds detected within 16 tar samples from five different production processes was produced. The 173 compounds identified within every sample may be of particular importance from a regulatory standpoint. This initial study indicates that different production processes produce tars with different chemical signatures and it can be further expanded upon by in-depth analysis of the different compound types. The number of compounds presented within this database clearly demonstrates the analytical power of GCxGC/TOFMS.

Pyrolysis Gas as a Renewable Reducing Agent for the Recycling of Zinc- and Lead-Bearing Residues: A Status Report

The topic “Zero Waste” has been in existence for several years in the industry, and the metallurgical industry has also made efforts to reduce the amounts of residues occurring and have started several investigations to cut down on metallurgical by-products which have to be landfilled. Especially, the additional costs for CO2 emissions in different metallurgical steps have led to investigations into alternative carbon carriers. Charcoal has been identified to serve as an ideal substitute due its CO2-neutrality. For the applications of this renewable carbon carrier in metallurgical processes, charcoal production by means of a carbonization process needs to be optimized. As a by-product during the heating of agricultural wastes or wood by excluding air, pyrolysis gas occurs. Due to the existence of combustible compounds in this gas, an application as a reduction agent instead of fossil carbon carriers in metallurgy is possible. Based on the prevention of dumping metallurgical by-products, an investigation has been developed to treat zinc- and lead-containing materials. To realize this, a dedicated process concept has been designed and developed. As the main focuses, the usage of the pyrolysis gas from charcoal production for the Waelz kiln process and the recycling of zinc- and lead-containing Waelz slag, resulting from the processing of steel mill dust in a vertical retort, have to be mentioned. Within this research, the process concept was executed from laboratory-scale up to pilot-scale testing, described in this article.

Recycling of Zinc- and Lead-Bearing Residues with Pyrolysis Gas

Efforts in the metallurgical industry for an approximation to the zero waste concept has led to many different investigations. Together with the greenhouse effect, CO2 emissions have caused additional costs for different process steps in the industry. For this reason, alternative carbon carriers have been sought, and charcoal was found to be an ideal substitute, due to its CO2 neutrality. In order to use it in the metallurgical industry, an optimization of the charcoal production through a carbonization process must be carried out. Beside the charcoal, pyrolysis gas also occurs during the heating of wood or agricultural wastes under the exclusion of air. Because of combustible compounds in this gas, it is possible to use it as a reduction agent instead of fossil carbon carriers. Together with the idea of preventing landfilling of metallurgical by-products, an investigation was carried out to treat zinc- and lead-containing materials. For this issue a special process concept was designed and developed. The main aspect was to recycle the zinc- and lead-containing Waelz slag, which results from the processing of steel mill dusts, in a vertical retort. Two different sizes of facilities were constructed to perform the reaction system of the solid Waelz slag with the gaseous reduction agent of pyrolysis gas.

Utilization of Estonian oil shale semicoke

In thermal processing of oil shale in vertical retorts huge quantities of a solid waste — semicoke are formed. It has been shown that circulating fluidized bed combustion of semicoke could be a promising technology allowing utilization of its high residual energy potential. The main parameters of combustion process and the additional heat produced were calculated and verified by combustion tests in a fluidized bed device with a thermal capacity of 50 kW th. The experiments indicated that semicoke with low moisture content can be burnt directly in fluidized bed. For the combustion of semicoke with higher moisture content (over 10%) about 10% of oil shale must be added. In addition, possibilities for utilizing residual carbon present in semicoke by obtaining carbon-rich materials with further production, for example, activated carbon were discussed. A series of experiments accompanied by SEM and EDAX analysis was carried out in order to elucidate the distribution of carbon and mineral part in semicoke and to find possibilities for their separation and subsequent enrichment. Different separation methods — selective grinding and subsequent screening, pneumatic separation and triboelectroseparation method were analyzed. It was shown that due to close integration of mineral and organic part in semicoke, the separation of carbon-rich ingredients by these methods was not enough effective to obtain enriched products suitable for the production of activated carbon.

THE INFLUENCE OF PHENOLS AND OTHER COMPOUNDS ON CHEMICAL OXYGEN DEMAND (COD) OF PHENOLIC WATERS FROM THE KIVITER PROCESS

In connection with increasing demand for oil shale phenols, Viru Chemistry Group, Ltd. has started co-processing of oils obtained at oil shale retorting in vertical retorts (the Kiviter process [1]) with oil fractions produced at Oil Plant of Narva Power Plants Ltd., where oil shale is processed in the solid heat carrier units (the Galoter process). However, co-treatment of oils has created some problems caused by an increase in the value of chemical oxygen demand (COD) in both the phenolic water and the dephenolized water. That, in turn, complicates biological treatment of the waters. A detailed investigation is needed to assess the influence of phenols and other organic compounds on COD of waters before and after dephenolation. Chemical oxygen demand, biological oxygen demand (BOD), total nitrogen content and total phosphorus content are the most significant parameters characterizing ecological danger of wastewaters. Among them COD is the most used. Under condition of joint discharge of municipal and industrial wastewaters into the soil or some water reservoir, COD value of biologically

リサイクリング・プロセスと操業 ＭＦ炉増処理に向けた諸改善

MF is a half shaft blast furnace which has been developed at Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. The MF has also been tested for treatment of various recycling materials and wastes. Now various secondaries and wastes (EAF dust, fly ash, zinc leaching residue, Cu sludge, etc.) are mainly treated. Powder materials are briquetted with reductant before being fed to the furnace. Products are crude zinc oxide, matte, non-hazardous slag and steam. Zinc and lead are recovered in oxide dust, and copper and silver are recovered in matte. The MF can be widely applied to many kinds of materials which contain such non-ferrous metal-valuables. In addition, the improvement in operation and technology has effectively made the unit capacity much larger by enrichment oxygen of air. The MF now has many advantages for treating these kinds of wastes.

Modeling sterilization process of canned foods using artificial neural networks

In order to model the thermal processing of canned foods, the neural networks technique was applied, whose aim was to determine the cold point temperature based on the initial process conditions and the retort's temperature. The network had the following input variables: the processing time, the retort's and cold point's temperature at the current time t i , and at previous times t i−1 and t i−2 . The output variable was the temperature of the cold point at the time t i+1 . For training the network, a time/temperature data set was obtained through the product processing in a vertical retort. The back-propagation through time and Jordan networks were trained and its generalization performance were compared. In this work, a better generalization capacity were obtained using the back-propagation through time network, which presented an average relative error of 2.2% between the calculated and predicted F values. The architecture of the selected network was the 5-8-9-1.

SOLID OIL SHALE HEAT CARRIER TECHNOLOGY FOR OIL SHALE RETORTING

Besides processing large-particle oil shale by vertical retorts, there are two commercial retorts (UTT-3000; UTT means ‘solid heat-carrier’) in operation for processing fine-grained oil shale by solid heat carrier technology (in publications referred to as the Galoter Process). Studies for development of the process were started over 50 years ago on OP-2 test retort in Kivioli followed by UTT-500 experimental retort with a throughput of 500 tons per day of oil shale. It was in operation in the period of 1963–1981. Successful studies and commercial experiments constituted the basis for a decision of construction of eleven retorts (UTT-3000) having a six times higher unit throughput rate in comparison with the UTT-500 retort. As Phase 1, by the 1980s at the Estonian Power Station two UTT-3000 retorts were constructed (The Oil Factory of Narva Elektrijaamad AS). These retorts were designed for supplying the Estonian Power Station with shale oil produced from unconcentrated fine-grained (energy) oil shale. The operating time of one retort was by design data 6800 hours per year, and simultaneous operation of two retorts was provided. In Fig. 1 the UTT-3000 retort flow diagramm (the Galoter Process) is given. The pyrolysis of dried oil shale is effected by mixing it with hot shale ash produced by combustion of oil shale semicoke (retorted oil shale). Therefore, the process is also referred to as the process with solid heat carrier. The UTT-3000 retorts with a unit throughput rate of ~3000 tons per day of raw oil shale started operation on December 31, 1979. The leading devel-

WASTEWATER TREATMENT IN OIL SHALE CHEMICAL INDUSTRY

Process water and phenols’ balances for the two processes of oil shale thermal treatment, Kiviter (in vertical retort) and Galoter (with solid heat carrier) were compiled. Options of wastewater treatment in the Kiviter process were analyzed in more detail. Laboratory experiments of biological oxidation of the process water after the dephenolation stage without other effluents and municipal wastewater were carried out. Experiments indicated that the oil shale phenols are generally quite easily degradable when the need for phosphorus is covered by added reagents. The experiments indicated that, compared to conventional aerobic bio-oxidation, the combined process, namely aerobic bio-oxidation with ozonation in re-circulation system, enabled to increase the efficiency of purification at relatively low ozone dosages. Application of ozone at moderate doses (up to 30 mg/L) improved the rate of pollutant removal. Injection of ozone at small dose – 2 mg/L – into the activated sludge in the bioreactor increased the sludge activity: the specific oxygen uptake increased about 15–20%. The biologically treated wastewater can be used as some kind of technological water (cooling water) after chemical precipitation and reduction of sulphate content. It can also been discharged to nature, but only after additional treatment to reduce nitrogen content and after filtration to remove the residual suspended solids.

Mathematical modelling of magnesium reductionin a novel vertical Pidgeon process

A mathematical model has been developed to simulate the phenomenon of heat transfer occurring during a novel magnesium reduction process - the vertical retort technology. The model was based on the control-volume finite difference approach. The simulations were run to determine the effect of various parameters, such as the diameter and thickness of the compound, and slot angle, on the magnesium reduction cycle time. The model predicted the temperature distributions, the heating curves, and the total process time. The predictions were used to optimize the magnesium reduction process including the dimensions of the retort, shapes of charged materials, and reduction cycle time. The computed results show that the utilization of the optimized process parameters leads to a decrease in reduction time and energy consumption, and an increase in production capacities and recovery rates. Consequently, the magnesium thermal reduction process is significantly improved in the vertical retort. The model has been verified in a demo-plant operation with an annual production capacity of 1200 ton magnesium.

Retrofitting of a vertical retort for on-line control of the sterilization process

A micro-controller-based retort control system for sterilization of foods was developed. The feature of this developed control system is that actual container cold point temperature is sensed on real time basis using temperature sensors. The on-line temperature is further processed using software to determine the sterilization value in terms of F o and is continuously displayed. The sterilization process is controlled until the set F o value is attained and at the end of the heating process cooling is automatically started. This ensures commercial sterility leading to higher nutrient retention and savings in energy by avoiding overcooking. This system can be easily incorporated onto the existing manually controlled batch retorts – horizontal or vertical. The system is more economical than the large sophisticated computer controlled systems presently available. It is mainly aimed at small and medium scale food processing industries having manually operated batch retorts.

Recovery of Carbon Values from Horizontal Zinc Retort Residues

Abstract Old horizontal and vertical retort Zn smelter sites are being examined by Federal and State environmental agencies because the residues and other wastes contain Pb and Cd. Residues at some of the sites have been declared hazardous wastes. Conservative estimates place the amount of these wastes at 36 Mmt. There are a number of sites with up to 0.4 Mmt of wastes in Kansas, Illinois, and West Virginia and one in Pennsylvania with 27 Mmt of wastes. In addition to their C content (20–30%), the residues represent a possible resource for Ge, Ga, In, Ag, Mn, Pb, and Zn. Samples obtained from several sites near Gas, Kansas are being used in research attempting to recover the unburned C and the metal values as separate products, leaving a nonhazardous residue that could be disposed of safely and economically. The residue was ground to liberate the C. Initial efforts to recover the C used oil agglomeration. This method recovered 67–781% of the C at grades of 66–79% but required large quantities of oil; the absence of agglomeration made separation difficult. Froth flotation has recovered 64–85% of the C in concentrates grading 54–84%.

三池製錬（株）における製鋼煙灰処理

MF is a half shaft blast furnace which has been developed at Mitsui Miike Smelter in the 1960's to treat vertical retort residue. The MF has also been tested for treatment of various recycling materials and wastes. Now various secondaries and wastes (EAF dust, zinc leaching residue, Cu-Ag sludge, etc.) are mainly treated. Powder materials are briquetted with reductant before being fed to the furnace. Products are crude zinc oxide, matte, non-hazardous slag and steam. Zinc and lead are recovered in oxide dust, and copper and silver are recovered in matte. The MF can be widely applied to many kinds of materials which contain such non-ferrous metal-valuables. In addition, the improvement in operation and technology has effectively made the unit capacity much larger. The MF now has many advantages for these treatment processes.