Pyritic sulfur, organic sulfur, and ash-forming minerals are removed from coal by a 2-stage alkaline treatment, using sodium carbonate or bicarbonate as the reagent. The first stage is an alkaline oxidation at moderate temperatures (130°-150° C.), and the second stage is a non-oxidizing alkaline treatment at a much higher temperature (250°-330° C.). The alkaline treated coal is extracted with an aqueous mineral acid, preferably hot aqueous sulfuric acid (H 2 SO 4 ) followed by washing with hot water. The resulting low-ash, low-sulfurcoal can
A lowash sample from the Ghouzlou coal deposit was subjected to sieve analysis and washability studies. According to the results of sieve analysis, the total ash content of the sample was around 12% which is acceptable for most of industrial applications. However, as the purpose of the study was to obtain a coal product with 5% ash content, the washability of +1 and -1 mm fractions was investigated through heavy media and flotation methods, respectively. Dense medium fractionation proved that it was feasible to obtain 5% ash products from size portions. Also, it was shown that the efficiency of process could be improved by using the coal blending technique. Furthermore, flotation experiments indicated that obtaining a 5% ash concentrate was not possible. However, the expected product could be gained by blending the flotation concentrates with the lowash size fractions.
ABSTRACT: Coal is a major source of energy. The available Indian coal quality is very poor having very high ash content and low calorific value. Indian coal generates a large quantity of ash as a by-product of combustion. The objectives of the present study were to reduce the ash content of coal to produce ultra-clean coal. The coal was treated with a dual chemical leaching process consisting of NaOH followed by HCl. During experiments, the concentration of NaOH was varied from 2.5 to 10 M with 1.4 N HCl. Effect of shaking speed and time was analysed at 0, 50, 100, 150 and 200 rpm and 1, 2, 3 and 4 hours respectively. After chemical leaching, the ash content was reduced from 35.33 to 0.98% in the ultra-clean coal. The concentration of alkali, shaking speed and time of duration were found as highly influencing parameters for the reduction of ash content in the coal. Moreover, the current study should result in a better option for the removal of ash content from low-rank Indian coals.
The results presented in Fig. 2a indicate that the activ- ity of the LiP enzymes in the second and fourth months for treatments C-P, C-AB and C showed significant dif- ferences (P < 0.05) relative to the control. At the sixth month, significant differences between treatments C-P and C-AB with respect to the control were seen. Treat- ment C-P presented significant differences from the control and other treatments during the months it was treated with LRC and CSB. Treatment C-P presented significant differences from the control and other treat- ments during the months it was treated with LRC and CSB. According to these results, it is not possible to attribute the activity of the LiP enzymes to inoculum that was applied because the strains CSB25, CSB13, CSB3 used in this bioassay have not been reported as produc- ing LiP enzymes, which are most associated with fungi . However, bacteria use non-enzymatic mechanisms for the solubilization of LRC, such as the production of surfactants, release of metal chelating compounds that bind the macromolecular structure of coal, and the pro- duction of alkaline substances that dissolve soluble mol- ecules and HS in the coal matrix ; possibly, this may stimulate the growth of native LiP-producing fungi or soil fungi found as accompanying flora in the pore spaces in the LRC-added soil. Due to its organic nature and con- tent of important elements for microbial nutrition such as nitrogen, sulfur, iron, carbon, oxygen and hydrogen and trace elements, it is a substrate for the colonization and growth of microorganisms, whose biological pro- cesses can be used as an energy source [9, 10].
At the Kelurahan Lamaru of RT 20 at the Balikpapan is consist of 152 KK that able to get clean water only 28 KK so the remains rely on the rain water and ground water that do not fulfill the standard so the population in general use low quality water. It has bad consequences for the community health such as irritation. The metal high concentration that causes the yellow color and odor that shows the presence of Fe content more than maximum content in water of 1.0 mg/l (Per Menkes RI No 416/Per/IX 1990). Some researches to decrease the metal content of the waste, one of them by using adsorption. The adsorption processes is one of alternatives to manage water that able to separate the impurities, the adsorption process is simple and economic . The used materials as the adsorbent by the Lamaru communities of Balikpapan only by using sands and pebbles then be placed at the drum but the obtained water still turbid and with little odor. The alternative materials for adsorbent in the process can be from various materials such as fly ashes. The advantages of the fly ashes are the low cost. Beside that the adsorbent can be used well for liquid waste and can be used to separate heavy metals and colored waste .
Mesophilic and moderately thermophilic acidophilic chemolithotrophic bacteria (AСB) and archaea, particu- larly, mesophilic representatives of the genus Acidithioba- cillus – Acidithiobacillus ferrooxidans and Acidithiobacil- lus thiooxidans dominate in the process of inorganic sul- fur’s removing. Information about the use of other ACB’s representatives in the process of coal desulfurization is not enough. There is information about the use for these pur- poses of a representative of the genus Acidithiobacillus – a strain of Acidithiobacillus ferrivorans, which has distinc- tive ability to grow on tripton and soy broth along with the properties common to typical representatives of Acidithi- obacillus. The strain isolated from the acidic drainage wa- ters of the Balıkesir field (Turkey) and identified by mo- lecular genetic analysis using 16S rRNA as Acidithioba- cillus ferrivorans was able to oxidize sulfur and iron .
Abstract The upgrading Kalimantan low rank coal is performed using slurry dewatering process in a stirred batch autoclave (inner volume of 5 liters) equipped with a con- denser, a pressure control valve (PCV), and a receiver. The experiment is carried out at 3.5 kg/cm 2 G nitrogen pressure, 250 o C heater temperature and 150 rpm agitator speed. Kero- sene and lowsulfur waxy residue (LSWR) are used as oil sol- vents. The fluidity of slurry is studied with the ratio of oil to coal (O/C) at 1.5 to 2 wt/wt and the concentration of LSWR at 0.5 to 2% in oil. The temperature profile during operation is evaluated to investigate the process performance. Moreover, pH, TSS and TDS contents in water product is also analyzed. A centrifuge separator (cap. 200 gram, 1000 rpm) is used to remove oil in coal slurry, and it is found that almost all added oil can be recovered. The study suggests that calorific value of upgraded coal (as received basis) increases sharply from 5,178 kcal/kg to 7342 kcal/kg, following drastic reduction in total moisture, from 25,5% to 4,97%. The contents of ash, volatile matter and elements do not change very much from that of raw coal. This phenomenon shows that no chemical reaction occurs in the process. The wastewater from the process is clean enough thereby a simple wastewater treatment is required in commercial plant. Re-absorption test shows that stable moisture content in coal is achieved at 7.5 wt% for 13 days. The temperature profile suggests that the slurry dewatering process can be applied effectively to Kalimantan low rank coals producing excellent upgraded coal characteristics.
Leaching of CFA in sulphuric acid resulted in simultaneous extraction of alumina. Under such conditions, total extraction efficiency of 94.2% alumina was obtained. Through a direct leaching process, amorphous and crystal phases of aluminium in coalash were leached under atmospheric pressure. For effective separation impurities other than Al3+ need to be removed through a suitable process. It is concluded that direct acid leaching at low concentration and ambient temperatures is not satisfactory for high recoveries of these metals from this fly ash. The concentrations of the acids were varied from low to concentrated reagent. Hence, low to moderate recoveries of metal values from fly ash by direct acid leaching is not surprising. The leachability of metals from fly ash depends on the nature of leaching medium, solid: liquid ratio, temperature and leaching time. The following conclusions can be drawn:
Abstract—The coal fly ashes contain toxic metals much higher concentrations than soil background levels that can be released into the environment through coal combustion processes. Disposal of coal fly ash in open and unlined ash ponds causes serious adverse environmental impacts to its elevated metals concentration and leaching into soils and groundwater. In the present research work, the water columns above the settled ash were sampled and cores of ash were collected over the course of 11 months from one class C and two class F ashes containing laboratory scale ash ponds. Samples were analysed for pH and metals. The arsenic, chromium were found to increase with aging of ash ponds containing class F ash while the concentration of all metals deceased in ash pond with class C ash. However, the free water column metals concentration was above 150 pbb, way above drinking water standard.
This confrontational rhetoric seeks to challenge the political system in a way that exposes imbalances of power. Short (1991) goes on to state that “agitative rhetoric” serves as a touchstone for measuring...individual level of commitment to the movement and how far they will go to purify the system” (p. 175). In the case of the CoalAsh Management Act, organizations who took this position were unsatisfied with any result other than the immediate removal, clean up, and relocation of all coalash ponds throughout the state. A representative from an environmental group with this perspective stated that “you can’t be an environmental advocate and be afraid to tell the truth and be afraid to rub some people the wrong way. Not ruffle a few feathers. You got to speak the truth and speak what’s right” (Environmental Organization Rep. 2, personal communication, 2014). While this unyielding approach allowed the organization to wholeheartedly stick to its mission, it did however affect its relationship with state legislators. According to this same organization, legislators did not want to meet with them or heed their advice. As described above, however, they were able to obtain access to meetings based upon relationships that other organizations had established.
Coal as an important natural resource still plays its irreplaceable role in 21 st Century, especially in those countries such as China, in which coal resources is relatively abundant [1-2]. Among those different kinds of coals, coking coal as an indispensable coal resource in metallurgical industry or in chemical industry, still has a large number market demand every year whether market economy model or planned economy model [3-5]. However, the associated elemental sulfur is also generated simultaneously while high quality coke is produced [6-8]. Currently these sulfurs mostly exist in the form of a mixture of sulfur formation and are discarded to environments. This disposal method occupies a lot of lands and pollutes the surroundings, but also it brings a huge waste of derived resources. As we know sulfur is an important raw material for the chemical, food, medicine and other industries [9-11], also there are a great deal of market demand in each year [12-13]. If these sulfurs can be recycled, then it will not only have a positive effect on our environments, but also the production chain of coal coking industry will be extended and the comprehensive utilization value of coal resources will be promoted, which will bring important economic significance to our societies. For solid mixture separation with sulfur, melting methods such as Frasch  and Sicilian [15-16] and sublimation methods  can be used to mine sulfurs from
Commission prior to construction to determine what scope of work may be grant eligible. As a general rule, direct access connection to individual units must be evaluated on a family-by-family basis. For example, if one unit of a duplex apartment is occupied by income-eligible renters, then a connection to that unit can be made. Costs to connect the other residence from a tap off of this line will not be paid by the grant. A connection to a multi-unit structure can be made at a common meter; however, any branch lines and/or meters must be verified for income eligibility on a unit-by-unit basis. Improvements to existing multi-unit complexes may be eligible depending on the potential of connecting low and moderate income residents.
We presented a mathematical model of low-reactive coal gasification in the upward annular channel, based on differential equations of the energy and mass conservation for a multi- component stationary flow. Gasification occurs in an air flow, it is possible to add water steam. The model uses matrixes and vectors to display main characteristic of gasification, which allows modifying it easily by adding new chemical reactions without changing main dependences of the model.
Traditionally, the treatment of soils with organic amendments is done with direct applications of humic extracts obtained by alkaline treatments of raw materi- als or by applying easily released HOM-enriched materi- als such as compost, biosolids, or peat materials. These options are not technically or economically feasible for increasing the HOM content of EM used to rehab soil after coal extraction in the “El Cerrejón” mine, since in these semiarid conditions these organic raw materials are missing; however, LRC is an available by-product of min- ing, but no studies have demonstrated the effects of using this material as a humic amendment applied directly to the soil. Since there are native strains of CSB that trans- form LRC and release HOM, the following hypothesis was proposed: if LRC is inoculated with CSB and applied to EM, the CSB will help release HOM and, conse- quently, this HOM will improve the properties of the EM,
Chemi cal deri vat i ves of aArt emi si ni n, a sesqui t erpene l act one produced by Art emi si a annua, i s are t he act i ve i ngredi ent i n t he most ef f ect ive t reat ment f or mal aria. Comprehensive phyt ochemical anal ysis of t wo cont rast ing chemot ypes of A. annua resul t ed i n t he charact eri sat i on of over 80 nat ural product s by NMR, more t han 20 of whi ch are novel and descri bed here f or t he f i rst t ime. Anal ysis of high- and l ow-art emisinin producing (HAP and LAP) chemot ypes of A. annua conf irmed t he l at t er t o have a l ow ΠΙάΙΠŋΤΚŋỲẄR⁷ŋŝΕΧΪΙΡΝΨΝΣΝΗŋΕΠΘΙΜﬃΘΙŋа⁶⁶ŋŝ⁶⁸ŦŋΧΙΘΫΗΪΕΨΙŦŋΛΙΣΙŋΙήΥΧΙΨΨΝΤΣūŋ′ΙΧΙŋέΙŋΨΜΤέŋΪΜΕΪŋΪΜΙŋűẃżŋΗΜΙΡΤΪﬃΥΙŋΕΗΗΫΡΫΠΕΪΙΨŋΜΝΛΜ l evel s of art emisinic acid, art eannuin B, epi-deoxyart eannuin B and ot her amorpha-4, 11-diene derived sesquit erpenes which are unsat urat ed at t he 11, 13-posit ion. By cont rast , t he HAP chemot ype is rich in sesquit erpenes sat urat ed at t he 11, 13-posit ion (di hydroart emi si ni c aci d, art emi si ni n and di hydro-epi -deoxyart eannuni n B), whi ch i s consi st ent wi t h hi gher expressi on l evel s of DBR2, and al so wit h t he presence of a HAP-chemot ype version of CYP71AV1 (amorpha-4, 11-diene C-12 oxidase). Our resul t s indicat e t hat t he conversi on st eps f rom art emi si ni c aci d t o art eannui n B, epi -deoxyart eannui n B and art emi si t ene i n t he LAP chemot ype are non-enzymat ic and paral l el t he non-enzymat ic conversion of DHAA t o art emisinin and dihyro-epi-deoxyart eannuin B in t he HAP chemot ype. Int erest ingl y, art emisinic acid in t he LAP chemot ype pref erent ial l y convert s t o art eannuin B rat her t han t he
This chapter concludes the research findings on strength and durability of fly ash geopolymer concrete in Chapter 4 and provides recommendations for future study. The present research has contributed to the present status of knowledge on the durability of fly ash geopolymer concrete in the seawater environment. The preliminary study is useful in determining the important parameters for further evaluation in this research. Mix design development of fly ash geopolymer concrete using the Taguchi optimization method increases efficiency when designing a mixture with various parameters involved. The strength, elastic modulus, water penetrability development of the optimum mixes until 365 days of the concrete age were revealed. The chloride ion penetration, and the strength, elastic modulus, porosity development, of concrete in continuous immersion and accelerated wetting-drying cycles were reported. This study also investigated the corrosion performance of fly ash geopolymer concrete using natural immersion and accelerated corrosion tests. The corrosion of steel bars in fly ash geopolymer concrete exposed to microorganism environment, which were firstly reported in this area, is an important step to elaborate on the effect of Microbiologically Influenced Corrosion (MIC) on this particular concrete. The main findings are given below.
manually repeated from different starting values and typ- ically converged to comparable minima solutions, espe- cially for fluxes that were estimated with high confidence (see Additional file 1: Tables S2, S3). The confidence intervals were calculated based on linear error propaga- tion (i.e. linearization of the equation system at the meas- urement timepoints) that is integrated in the gPROMS software package. For the mass isotopomer measure- ments an error of 3% (absolute) was assumed. Excep- tion is the measurement of Oaa which was less reliable because of the very low concentration of Oaa. Here 30% error were used. This estimated errors not only reflects the MS noise but also the non-ideal plug-flow within the BioScope reactor , i.e. the sampling time point is a (narrow) distribution of different time points. The errors of the MS/MS measurements itself are estimated to be between 0.5 and 2% . The standard deviation of the biomass specific extracellular rates was also calcu- lated using linearized error propagation of the black-box model using PWA rate functions. The required standard deviations of the observables (i.e. succininc acid, biomass and other concentrations) was calculated from the repet- itive measurements, i.e. the average standard deviation of all observed timepoints.
produced in the flotation plant assaying 83% total carbonate is the feed to the cement kiln. Limestone up gradation process comprised of multistage crushing, grinding and flotation. The flotation plant is operated in two parallel lines at a rated capacity of 60-65 tph per line. Limestone received in the cement works from Madukkarai mine and +15mm fraction from Walayar mine in1:1 ratio is mixed, crushed and screened at site in jaw and impact crushers to all –15mm size. This blend assaying 76-77% Total Carbonates forms the feed to two ball mills operated in close circuit with 350mm hydrocyclones. Overflow from the hydrocyclone is deslimed in a cluster of 100mm hydrocyclones. The overflow joins the concentrate thickener whereas the underflow constitutes the feed to flotation. Flotation is carried in two parallel batteries, one of Dorr-Oliver make and other of Outokumpu make equipped with automatic level controller. Each flotation battery has 12 cells. First 8 cells produce concentrate and last 4 cells are used as scavenger cells. The scavenger concentrate is fed back to the conditioner, whereas the scavenger tails forms the final rejects. The concentrate joins the thickener. Thickener underflow assays around 83% Total Carbonates and is the feed to cement kiln. The reject assays around 25-30% Total Carbonates. Anionic collector used in the flotation is a mixture of soap, resin and caustic. The reagents consumption is 1 kg/t of ROM and is partly added in the conditioner and remaining in the various flotation cell. Review of literature on flotation of limestone indicate that anionic direct flotation dominates over cationic inverse flotation. [2-10] The aim of the work was to evolve nil waste
Another reason may be the effect of water to geopolymer solid ratio or water to fly ash ratio. For the synthesis of geopolymeric material in the initial stage, water content plays a central role. It acts as the medium for dissolution and polymerization of Al and Si precursors. It can be seen from Table 2 that as molarity increases water to Geopolymer solid as well as water to fly ash ratio increases. The results of compressive strengths of geopolymer mortars are also represented in Figure 4 based on water to geopolymer solid ratios varying from 0.26 to 0.32 or water to fly ash ratio varying from 0.28 to 0.35 at 80°C. The results obtained here are in line with the results obtained by the previous researchers [36-37].