In this study, a research was conducted to recover metallic zinc and pig iron and to improve the purity and the recovery rate through a reduction process for zinc and iron in the byproducts that are generated after steelmaking dust treatment. As the result of the calcination, it was confirmed that Cl (6.06%) and K (3.37%) decreased to Cl (2.75%) and K (0.22%), respectively. For the zinc powder that was recovered with reaction temperature of 1100°C, reaction time of 4 hours, and argon gas of 1L/min as the optimal conditions. The measurement for the purity of zinc was 99.8% and the recovery rate was 92.14%. The melt reduction for recovering pig iron from the residue was reacted under reaction temperature of 1600°C, flux composition (CaO:SiO2) of 1:1, and reducing agent infusion ratio (residue: C) of 14:1, and the pig iron was measured to have a purity of 87.7% and a recovery rate of 91.81%.

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and

subsequent fires caused by coal dust can result in significant property damage, loss of life in underground

coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted

research on coal dust explosions until 1996 when it was dissolved. In the following years, the American

Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard

test method characterizing the “explosibility” of particulate solids of combustible materials suspended

in air. The research presented herein investigates the explosive characteristic of Pulverized Pittsburgh

Coal dust using the ASTM E1226-12 test standard. The explosibility characteristics include: maximum

explosion pressure, (Pmax); maximum rate of pressure rise, (dP/dt)max; and explosibility index, (Kst). Nine

Pulverized Pittsburgh Coal dust concentrations, ranging from 30 to 1,500 g/m3, were tested in a 20-Liter

Siwek Sphere. The newly recorded dust explosibility characteristics are then compared to explosibility

characteristics published by the Bureau of Mines in their 20 liter vessel and procedure predating ASTM

E1126-12. The information presented in this paper will allow for structures and devices to be built to

protect people from the effects of coal dust explosions.

Waterproof lime dust used in coal mines is an important element in the system of protection against explosions. This is one of the oldest methods used to prevent coal dust explosions and, according to an expert’s opinion, it will remain so for a long time. T he work is a summary of research on the development of a new method of producing waterproof limestone dust to use it as an anti-explosive powder in coal mines. The typical method of hydrophobic dust production (milling limestone with stearic acid) is no longer profitable due to the restructuring of the mining industry. The main research was conducted on raw materials traditionally used during the production of anti-explosion powder, namely limestone meal with a grain size diameter equal to 80 μm (Czatkowice Limestone Quarry) and stearic acid as a modifier. Silicone preparation and bituminous preparation (Bitumenovoranstrich) were used as additional modifiers. The hydrophobization process was conducted with the use of different techniques: from stearic acid ether solution, from stearic acid vapor, from methyl silicone resin or bituminous preparation solutions. A series of research on modified powders to determine hydrophobization and flow properties was conducted. Depending on method of hydrophobization, the test of “floating on water”, the extraction of stearic acid was carried out, water contact angles on compacted material were determined, the thermal decomposition of powder was made. The increase in moisture after wet storage was indicated. The flow properties of powders were measured with the use of the Powder Characteristics Tester. The evaluation of the suitability of each hydrophobization methods in achieving the intended purpose was valued.

Industrial steelmaking (EAF) flue dust was characterized in terms of chemical and phase compositions, leaching behaviour in 20% sulphuric acid solution as well as leaching thermal effect. Waste product contained about 43% Zn, 27% Fe, 19% O, about 3% Pb and Mn and lesser amounts of other elements (Ca, Si, Mo, etc.). It consisted mainly of oxide-type compounds of iron and zinc. Dissolution of metals (Zn, Fe, Mn) from the dust was determined in a dependence of solid to liquid ratio (50-200 g/L), temperature (20-80oC) and leaching time (up to 120 min). The best result of 60% zinc recovery was obtained for 50 g dust/L and a temperature of 80oC. Leaching of the material was an exothermic process with a reaction heat of about –318 kJ/kg. Precipitation purification of the solution was realized using various ratios of H2O2 to NH3aq. A product of this stage was hydrated iron(III) oxide. Final solution was used for zinc electrowinning. Despite that pure zinc was obtained the highest cathodic current efficiency was only 40%.

The: PM2.5/PM10 ratio expresses the anthropogenic share in atmospheric dusl. Very high values or this ratio, i.e. high contribution or PM2.5 to PM10. have occurred recently in atmospheric air within European indusuializcd areas. The paper compiles results of three year pair wise measuring ofconcentrations or PM2.5 and PM2.5-PM10 and compares shares or PMM2.5 in PM10 al three urban background sites in Upper Silesia Poland I towns or Zabrze. Katowice and Częstochowa). At all the three local ions, the PM2.5/PM10 ratio nr daily conccntrations nr dust only occasionally differed considerably from the PM2.5/PM10 ratios for the seasonal and yearly concentrations that, in turn. did not differ from the PM2.5/PM10 ratios al urban sites in Europe.

Aspiration dust probes of some isokinctic samplers have such a construction that enables them to measure the gas velocity at the point they arc placed in a duct, the measurement being required for maintaining isokinctic conditions and in determining the dust mass flow rate in the duct. The gas velocity is correlated with a probe specific pressure difference, a quantity measured directly when the train is in operation. This relationship is a mclrological characteristic of a given probe, being established in a calibration procedure. Two types of the above-mentioned probes, namely a pressure balance-type and an in-stack filtration probes (in two versions) combined with a type S velocity sensor, have been tested. The behaviour of the characteristics of the probes was studied in the flows of different turbulence at a laboratory stand. The achieved results, presented in the paper, show that the turbulence state of gas flow is the factor that shapes the mctrological characteristics. Facing the fact that the turbulence of gas flow in industrial installations is not identified during the dust concentration gravimetric measurements, this parameter constitutes a source of uncertainty of the gas velocity measurement. For the probes under test, the values of this uncertainty, varying with the gas velocity, were determined. The test and calculation procedures were described.

In this study, the aim was to model the toxic effect of copper (Cu) and analyse the removal of Cu in aqueous Saharan and non-Saharan mediums by Lemna minor. Two separate test groups were formed: with Saharan dust (S) and without Saharan dust (WS). These test groups were exposed to 3 different Cu concentrations (0.05, 0.50 and 5.00 ppm). Time, concentration, and group-dependent removal effi ciencies were compared using the non-parametric Mann-Whitney U test and statistically signifi cant differences were found. The optimum removal values were tested at the highest concentration 79.6% in the S medium and observed on the 4th day for all test groups. The lowest removal value (16%) was observed at 0.50 ppm on the 1st day in the WS medium. When the S medium and WS medium were compared, in all test groups Cu was removed more successfully in the S medium than the WS medium contaminated by Cu in 3 different concentrations of (0.05 ppm, 0.50 ppm, 5.00 ppm). The regression analysis was also tested for all prediction models. Different models were performed and it was found that cubic models show the highest predicted values (R²). The R² values of the estimation models were found to be at the interval of 0.939–0.991 in the WS medium and 0.995–1.000 in the S medium.

Polychlorinatcd dibenzodioxins and dibcnzofurans (PCDD/Fs) arc present in the air either adsorbed on particulate matter or as vapor (minor part). They arc known to be effective carcinogenic and mutagenie agents. In this study dust samples from Lublin were collected for twelve months and analyzed for PCDD/Fs content. For the analysis of these samples classical extraction with a Soxhlet apparatus, double step clean-up based on SEC and charge-transfer interactions chromatography, and final analysis with GC-MS were applied.

Polychlorinated dibenzodioxins and dibenzofurans are present in the air either adsorbed on particulate matter or as vapor (minor part). They are most known carcinogens and mutagens. In this study dust samples from Lublin were being collected for 12 months and analyzed for the PCDD/Fs content. For the analysis of these samples classical extraction with Soxhlet apparatus, double step clean-up based on SEC and charge-transfer interactions chromatography, and finally analysis with GC-MS were applied. Results of the determinations were compared with results obtained by other authors.

In this study, laboratory-scale experiments were carried out to investigate the effects of microwave-assisted alkaline leaching on the treatment of electric arc furnace dusts to recover zinc and lead. Microwave treatment is a new innovative technology in waste treatment and now is an attractive advanced inter-disciplinary field and also environmental friendly. The highest zinc extraction, 50.3% in 60 minutes using 5 M NaOH at 750 W and L:S ratio 20, and lead extraction up to 92.84% was achieved in these same conditions but in 30 minutes. Compared with conventional leaching, the top extraction rate using MW-assisted leaching was higher by 16% (Zn) and 26% (Pb). Zinc presents in the flue dust in the form of franklinite (ZnFe2O4), its leaching in sodium hydroxide does not occur under the examined conditions, because it is enclosed in a matrix of iron.

The cement production process is associated with the emission of dust. These are mainly CKD (cement kiln dust) and BPD (by-pass dust), classified as wastes from group 10 – Wastes from thermal processes, subgroups 10 and 13 – wastes from manufacture of cement, lime and plaster and articles and products made from them. Cement kiln dust is a waste of variable composition and properties, which makes it a difficult material to recover. The main directions of recovery presented in the world literature indicate the use of dust from cement kilns in cement, mortar and concrete production, the production of bricks and in order to improve soil quality and wastewater treatment. Factors affecting chemical and phase compositions of dust from cement kilns are the reason why each waste should be analyzed individually. The paper presents the results of the analysis of the cement kiln dust after dedusting cement kilns and two bypass dusts. Analysis of the chemical composition has shown significant concentrations of chlorine, potassium and calcium in all wastes. The content of: Si, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, and Bi has also been confirmed. The analyzed dusts were characterized by the presence of carbonates (calcite, dolomite, and arcanite), quartz, alite, belite, sylvine, anhydrite, and portlandite in their phase composition. The leachates which were characterized by an alkaline reaction. In terms of leachability, high concentrations of chlorine ions in the analyzed dust leachates were confirmed, which significantly limits their use.

The heavy metal content is one of the criteria for foundry dust commercial use. To assess the possibility of foundry dust use, it is necessary to analyze its composition, including the content of basic heavy metals, and its mechanical properties. The paper presents the results of research on foundry dust from one of the Polish foundries. The aim of the study was to assess the waste management based on its composition and content of heavy metals. Dust samples were taken from one of the Polish foundries, producing iron and steel castings. Samples were taken from several places in the foundry, i.e. from electric furnace dust collectors, shock grating unit, transport of moulding sands unit, pneumatic blast cabinet units and the regeneration of spent foundry sand units. Samples were taken twice from each place at the turn of 2017–2018. The total content of heavy metals such as Cd, Pb, Cu, Zn, Cr, Ni, Mn, and Fe for recovery and additionally Hg as environmental pollution was analyzed. Based on the results of the research, it was found that the dust from foundry furnaces and pneumatic cleaners can be used in metallurgy due to a high percentage of iron. It was found that the dust from casting cleaning, transport and regeneration department can be used in the cement or construction industry. In addition, an assessment of the mercury content showed that the re-use of this dust would not cause an environmental hazard. It was found that the profitability of foundry dust use depends on the stability of its composition and requires testing for each batch of dusts.

Froin January 2006 on, a continuous experiment consisting in determinations of granulometrie composition of the airborne dust has been performed in the Institute of Environmental Engineering of PAS, Zabrze. The investigations include measurements of concentrations of PM1 - the suspended in ambient air particles of the aerodynamic diameter not grater than I μm - by using the PM10 Dekali impactor. The results of twelve month measurements (January - December 2006) arc presented in the paper: the granulometrie composition of total suspended dust (PM10, PM2.5, PM1) in winter and summer at an urban background site in the Silcsian Agglomeration. Monthly and seasonal average concentrations of PM I O, PM2.5 and PM1 were computed.

The article concerns investigations over benefits of application of HRC devices into sulphide copper ore processing plant. High pressure comminution appears to be very effective technology in hard ore processing circuits, especially in terms of energy consumption. This can be particularly observed in downstream grinding and beneficiation operations. A series of pilot-scale crushing tests in HRC roller press for various levels of operating pressure, were performed. HRC crushing effectiveness along with downstream grinding process course for each crushing product were also under analysis. The investigations were supplemented by analysis of flotation process effectiveness and impact of the process of high-pressure comminution on environment (dust emission). The results of investigation show that operating pressure level influences the obtained comminution results (comminution degree, yield of finest particle size fractions). The grinding effectiveness, measured through production of the finest particle size fractions was significantly influenced by the operating pressure. The results show that higher values of operating pressure (4.0 and 4.5 N/mm2) are not as efficient within this scope as the pressure 3.5 N/mm2. Dust emission is also correlated with the operating pressure value.

Environmental risks associated with Co, Cr, Cu, Mn, Ni, Pb, V and Zn in street dust collected from Baotou, a medium-sized industrial city in a semi-arid area of northwest China, were assessed by using enrichment factor and the potential ecological index. Their spatial distributions and sources in the dust were analyzed on the basis of geostatistical methods and multivariate statistical analysis, respectively. The results indicate that street dust in Baotou has elevated heavy metal concentrations, especially of Co, Cr, Cu, Pb and Zn. Co in the dust was significantly enriched. Cr and Pb were from moderate to significant enrichment. Cu and Zn were from minimal to moderate enrichment, whereas Mn, Ni and V in the dust were from deficient to minimal enrichment. The ecological risk levels of Co and Pb in the dust were moderate to considerable and low to moderate, respectively, whereas those of other heavy metals studied in the dust presented low ecological risk. Different distribution patterns were found among the analyzed heavy metals. Three main sources of these heavy metals were identified. Cr, Mn, Ni and V originated from nature and industrial activities. Cu, Pb and Zn derived mainly from traffic sources, and Co was mainly from construction sources.

The article presents the results of research aimed at increase of the efficiency of gas cleaning equipment based on the Venturi tube using high-intensity ultrasound. The model based on known laws of hydrodynamics of multiphase mediums of dust-extraction in Venturi scrubbers was proposed. Modification of this model taking into account ultrasonic field allows evaluating optimum modes (sound pressure level) and conditions (direction of ultrasonic field, square and number of ultrasonic sources) of ultrasonic influence. It is evaluated that optimum for efficient gas cleaning is the mode of ultrasonic action at the frequency of 22 kHz with sound pressure level of 145. . . 155 dB at the installation of two radiators with area of 0.14 m2, four radiators with area of 0.11 m2 or six radiators with area of 0.08 m2 at the angle of 45 degrees to the axis of Venturi tube. Numerical calculations showed that realization of ultrasonic action is the most efficient for the reduction (up to 15 times) of the content of fine-dispersed fraction (2 μm and less), which is impossible to extract without ultrasonic action. The received theoretical results were confirmed by industrial testing by typical dust-extraction plant and used as foundations of development of apparatuses with the radiators of various sizes.

In this study, solidification/stabilization (S/S) of electric arc furnace dust (EAFD) which is generated during the production of steel from scrap metals and classified as hazardous waste were investigated by using different ratios of cement and low grade MgO (LG MgO) as binding agents. Type I PC 42.5 R portland cement and LG MgO which contains 70–80% MgO were used. S/S blocks that contain different ratios of binding agents which have 1/0.5 – 1/1 – 1/2 – 1/3 – 1/4 – 1/5 cement/LG MgO ratio and S/S blocks which contain only cement and no LG MgO agents were prepared. These blocks, which contain 3 different waste ratios according to weight, 20%, 30% and 40% respectively, were produced and exposed to 28-day water purification. At the end of the purification process, S/S blocks were extracted using TCLP (Toxicity Characteristic Leaching Procedure) tests in order to determine the leaching behavior of Zn, Pb, and Cd in S/S blocks. By the end of this study, it was concluded that the recovery of EAFD is possible and applicable by immobilization. The findings of the study concluded that environmental performances or structural properties of blocks contain 30% waste by weight are suitable. This method is a proper one for recovering and treatment of EAFD with mixture of cement and LG MgO.

Until now, dust arising from lime manufacture has been considered harmless to the environment so it has been investigated marginally from the standpoint of environmental protection, especially when it came to magnetic properties and heavy metal content. The aim of the research was filling the gap in this area. The research comprised measurements of magnetic susceptibility, the content of heavy metals, reaction (pH) and specific conductivity of lime dust and also raw material and fuel used for lime production. The samples were taken from one of the lime plants located in Opole Province. Similar investigations were also performed for dust taken from the nearby cement plant using dry method of cement production. It was proven that magnetic susceptibility, heavy metal content and conductivity of lime dust was lower in comparison to cement dust, which resulted from the fact that the lime plant used neither low raw materials nor additives. Due to the high atmosphere dust level in the vicinity of the investigated plants, extremely basic reaction of the tested dust and high content of metals, the studied dust cause alkalization of soils and contribute to the increase of heavy metal content in soils, posing a threat to the environment.

Dust generated at an electric arc furnace during steel production industry is still not a solved problem. Electric arc furnace dust (EAF) is a hazardous solid waste. Sintering of well-prepared briquetted mixtures in a shaft furnace is one of possible methods of EAFD utilisation. Simultaneously some metal oxides from exhaust gases can be separated. In this way, various metals are obtained, particularly zinc is recovered. As a result, zinc-free briquettes are received with high iron content which can be used in the steelmaking process. The purpose of the research was selecting the appropriate chemical composition of briquettes of the required strength and coke content necessary for the reduction of zinc oxide in a shaft furnace. Based on the results of the research the composition of the briquettes was selected. The best binder hydrated lime and sugar molasses and the range of proper moisture of mixture to receive briquettes of high mechanical strength were also chosen and tested. Additionally, in order to determine the thermal stability for the selected mixtures for briquetting thermal analysis was performed. A technological line of briquetting was developed to apply in a steelworks.

The results of investigations of the granulation process of foundry dusts generated in the dry mechanical reclamation process of used sands, where furan resins were binders are presented in the paper. Investigations concerned producing of granules of the determined dimensions and strength parameters. Granules were formed from the dusts mixture consisting in 50 mass% of dusts obtained after the reclamation of the furane sands and in 50 mass % of dusts from sands with bentonite. Dusts from the bentonite sands with water were used as a binder allowing the granulation of after reclamation dusts from the furane sands. The following parameters of the ready final product were determined: moisture content (W), shatter test of granules (Wz) performed directly after the granulation process and after 1, 3, 5, 10 days and nights of seasoning, water-resistance of granules after 24 hours of being immersed in water, surface porosity ep and volumetric porosity ev. In addition the shatter test and water-resistance of granulate dried at a temperature of 105oC were determined. Investigations were performed at the bowl angle of inclination 45o, for three rotational speeds of the bowl being: 10, 15, 20 rpm. For the speed of 10 rpm the granulation tests of dusts mixture after the preliminary mixing in the roller mixer and with the addition of water-glass in the amount of 2% in relation to the amount of dust were carried out. The obtained results indicate that the granulator allows to obtain granules from dusts originated from the reclamations of moulding sands with the furane resin with an addition of dusts from the bentonite sands processing plants.

The article presents research results of physico-chemical and environmental issues for the dust generated during dedusting of the

installation for the processing and preparation of moulding sand with bentonite. Particular attention was paid to the content of heavy

metals and emission of gases from the BTEX group, which is one of the determinants of the moulding sands harmfulness for the

environment. The analysis of heavy metals in the test samples indicate that there is an increase of the content of all metals in the dust

compared to the initial mixture of bentonite. The most significant (almost double) increase observed for zinc is probably related to the

adsorption of this element on the dust surface by contact with the liquid metal. The study showed, that dust contained more than 20% of

the amount of montmorillonite and had a loss on ignition at a similar level. The addition of 1% of dust to the used moulding sand results in

almost 30% increase in the total volume of gases generated in casting processes and nearly 30% increase of the benzene emission.

The problem related to the management of post reclamation dusts generated in the reclamation process of waste moulding sands with

organic binders is presented in the hereby paper. Waste materials generated in this process are products hazardous for the environment and

should be utilised. The prototype stand for the utilisation of this dangerous material in its co-burning with coal was developed and patented

in AGH in Krakow. The stand was installed in one of the domestic casting houses. As the utilisation result the transformed waste product

is obtained and its management in the production of ceramic materials constitutes the subject of the presented publication.

Foundry dust from blasting and grinding of castings contain a high amount of iron, ergo it is possible its recycling in foundry process. Dust was compacted by briquetting, two kinds of briquettes were prepared (A contained 95% magnetic part of dust from casting blasting +5% bentonite and B contained 95% mixture of dust from casting grinding and magnetic part of dust from casting blasting + 5% bentonite) and used as a part of charge into the electric induction furnace. It was found that addition of briquettes has had an influence of a chemical composition of cast iron above all on content of sulphur, phosphorus and silicon. It was not reflected in decrease in tensile strength and in microstructure. Yield of metal from briquettes was not lower then 70%.