Dust Treatment Research Articles

An efficient and affordable hydrometallurgical process for co-treatment of copper smelting dust and arsenic sulfide residue

We developed a novel method for comprehensive treatment of copper smelting dust (CSD) and arsenic sulfide residue (ASR) using three processes: leaching CSD by sulfuric acid, Cu precipitation with ASR, and FeSO4·7H2O/O2 co-oxidizing and precipitating As. The novel method not only realizes the recovery of valuable metals from dust, but also removes and solidifies As in CSD and ASR in the form of scorodite to achieve harmless treatment. With sulfuric acid as leaching agent, the leaching efficiencies of Cu, Zn and As reached 87.23%, 93.07% and 95.21%, respectively, under the optimum conditions. Subsequently, Cu in CSD leaching solution was precipitated in the form of CuS by ASR, and the Cu precipitation percentage reached 97.39% and 94.86 wt. % of As in ASR entered the solution under the optimum conditions. Finally, FeSO4·7H2O/O2 was used to co-oxidize As(III) and simultaneously precipitate the As in the form of scorodite. The oxidation percentage and precipitation percentage of arsenic reached 98.73% and 96.77%, respectively. The leaching concentration of As in the arsenic precipitate residue (APR) was only 0.17 mg/L in the toxicity characteristic leaching procedure (TCLP). The arsenic precipitate solution can be directly used to recover Zn.

Crushed amygdaloidal basalt rock and its effects on tomato production

Abstract
 Sustainable agriculture plays an important role in agricultural productivity, in which it seeks to reduce dependence on conventional synthetic fertilizers (imported from Europe) and promote the use of alternative, low-cost and environmentally friendly sources. An experiment was carried out in the municipality of Santa Maria, Rio Grande do Sul, Brazil, with the objective of evaluating the efficiency and agronomic viability of using a mineral product (amygdaloid basalt powder) as an agricultural input on tomato productivity Solanum lycopersicum. The experimental design used was randomized blocks with six treatments and four replications, at doses 0 (treatment 1 - control), 1.0 ton ha-1 of rock dust (treatment 2), 2.5-ton ha-1 of rock dust (treatment 3), 3.5-ton ha-1 of rock dust (treatment 4), 4.5-ton ha-1 of rock dust (treatment 5), and recommended fertilization for tomato 5-20-20 NPK (treatment 6 - standard). The treatments were applied in December 2018 and the transplant took place in February 2019. According to the conditions under which the experiment was submitted and analyzing the results obtained, it can be inferred that the application of 1-ton ha-1 of amygdaloidal basalt in the soil increased parameters such as root length, stem diameter, green and dry mass of shoots and roots, number of flowers/plants, number of fruits/plant and productivity in tomato Solanum lycopersicum. It is a viable, sustainable, and low-cost strategy that contributes to the achievement of the Sustainable Development Goal (SDG 2) and can be replicated in Brazil and worldwide.

Treatment of strong alkaline wastewater from neutral leaching of EAF dust by precipitation and ion exchange

Neutral leaching or water washing is used for Cl− and partially Ca2+ ion removal in order to save the leaching reagents for the next steps in hydrometallurgical treatment of electric arc furnace dust. This pre-treatment of the material leads to the generation of strong alkaline (pH = 11.9–12.7) leachate (wastewater), which underlies precipitation of Ca and other accompanying metals. This work presents results from the study of various economically differing (cost and time) techniques for elimination of these disadvantageous phenomena. The aim of the experimental study was to obtain water suitable for reuse in the leaching or for discharge into a recipient in accordance with valid legislation. The experiments were focused on the removal of precipitates, or metals which create the precipitates, and pH decreasing. Our results indicate that five-minute agitation of 4 g solid NaHCO3 and 1 L of neutral leachate and subsequent ion exchange in the sequence of strong-acid cation and strong-base anion exchange treatment led to the acquisition of water without creation of precipitates, with pH below 8.5 and conductivity approx. 0.03 mS. The removal of Cl− ions was not complete.

Methods for Obtaining Phosphorus-Containing Fertilizers Based on Industrial Waste

This article discusses the method of obtaining phosphorus-containing components from cottrel dust from the industrial wastes of the New-Jambul phosphorus plant. Accumulated industrial waste heavily pollutes the environment and has a direct impact on all living things. Therefore, their processing is of special interest for the state and grant programs have been allocated in order to obtain new valuable substances. In order to solve these problems, a number of experimental works have been carried out to study the chemical and mineralogical composition and chemical structures during the heat treatment of cottrel dust—the waste of phosphorus production. The optimal parameters of the process of obtaining mono-calcium phosphate from cottrel dust were determined and the process of crystallization of mono-calcium phosphate was studied. A method has been developed for obtaining a phosphorus-containing fertilizer based on cottrel dust from the industrial waste of the New-Jambul phosphorus plant by means of sulfuric acid solutions. The advantage of the resulting phosphorus-containing fertilizer is that it has a high solubility and digestibility of phosphorus plants. They are also high in phosphorus-containing substances that ensure the growth and yield of agricultural plants. The developed method for obtaining phosphorus-containing fertilizers is aimed at reducing the accumulated industrial waste, which in turn allows you to regulate and improve the environmental situation in the region.

Ecological Footprint Assessment of Concrete: Partial Replacement of Cement by Water Treatment Sludge and Stone Dust

Currently, most concrete industries use conventional cement (Ordinary Portland Cement) as a binding material which involves natural resource depletion, colossal CO2 emissions, and a huge energy supply. The present study addresses this critical issue by using stone dust (sun-dried and calcinated) and water treatment sludge (sun-dried and calcinated) to replace cement partly in M20-grade concrete production. The environmental impact of ready-mixed concrete (RMC) production with conventional cement and partially replaced cement by other cementitious material, i.e., stone dust and water treatment sludge in concrete, is assessed through ecological footprint (EF) indicator. Moreover, a novel sustainability index is proposed for ready-mixed concrete plants to scale the environmental impact of different types of concrete (or grades) on the sustainability scale (environmental, social, and economic sustainability). The results showed that the sun-dried water treatment sludge and sun-dried stone dust could effectively replace cement (15% by weight) in the concrete, with a comparable compressive strength over the M20 ready-mixed concrete. The EF of conventional M20 RMC is estimated to be 0.02295 gha/m3. The EF of concrete (with sun-dried water treatment sludge) is reduced by 13.14% of the conventional ready-mixed concrete. The Ecological Sustainability Index (ESI) of the ready-mixed concrete plant is estimated to be 718.42 $/gha. Using water treatment sludge and stone dust in concrete production can be an innovative solution because it simultaneously solves the problem of waste disposal, large carbon emissions, cost, and high environmental impact.

Electric steelmaking dust as a raw material for coagulant production

The paper describes the issues associated with waste generated during steel production and processing, in particular the dust from electric arc furnaces (EAF). An effective solution for the disposal of such waste is its involvement in processing to obtain valuable products. This paper studies the physical and chemical properties of EAF dust produced during the smelting of metallized pellets and captured by the dust and gas cleaning system of the steel-smelting shop at the Oskol Electrometallurgical Combine, Belgorod Region. The results obtained in the study of the chemical and disperse compositions of dust, the microstructure of the surface made it possible to propose the use of dust as a raw material for coagulant production. The conditions of acid-thermal treatment of dust are determined, contributing to the partial dissolution of iron (II), (III), and aluminium compounds, which ensure the coagulation processes during wastewater treatment. Model solutions show high efficiency (> 95 %) of water treatment from heavy metal ions by modified EAF dust.

SiO2 dust induces inflammation and pulmonary fibrosis in rat lungs through activation of ASMase/Ceramide pathway.

The role of ASMase/Ceramide signaling pathway in the development of silicosis needs to be verified by in vivo experiments. We investigated the role of the ASMase/Ceramide signaling pathway in the progression of silicosis and the effect of desipramine (DMI)(1mg/mL) on the development of silicosis, by establishing a silica(1mL, 50mg/mL) dust-contaminated rat silicosis model and administering the ASMase inhibitor, DMI, to the dust-contaminated rats. The results showed that levels of IL-1β and IL-6 were increased in the lung tissues of the rats in the dust-contaminated group at the initial stage after dusting, the inflammatory cell aggregation in the lung tissue was increased. With time progression, the hydroxyproline content in the lung tissue increased, and α-SMA, collagen I and vimentin substantially increased, suggesting that silicosis were formed in the lung tissue of the rats 28 days after SiO2 dust treatment. Moreover, the levels of ASMase, ceramide and S1P were increased in the lung tissue of rats. The expression of β-catenin, fibronectin and caspase-3 protein was increased, and E-cadherin protein expression was decreased in the lung tissue of the rats in the late stage of dust contamination. The ASMase and ceramide in the lung tissues of the rats in the DMI intervention group were reduced, as were the lung tissue inflammation levels, collagen expression, and lung fibrosis. These results suggest that SiO2 dust may activate the ASMase/ceramide signaling pathway in rat lung tissue, promoting pulmonary fibrosis. DMI inhibited these activation, attenuated apoptosis and blocked epithelial-mesenchymal transition and halted silica dust-induced silicofibrosis.

Development of Dust Monitoring in Urban Construction Sites and Suggestions on Dust Control

Construction site dust is one of the main sources of urban air pollution. In order to improve urban air quality and reduce the probability of respiratory diseases among construction workers, effective measures must be taken to control construction site dust. Dust monitoring is an important measure to reduce construction pollution to the surrounding environment. Vigorously developing dust monitoring is the only way to build a civilized construction and green city. Improving dust monitoring at urban construction sites has important practical significance for urban air quality control and accurate treatment of dust at construction sites. Dust monitoring can improve the appearance of the city, increase the investment of investors, and promote the economic development of the city. At the same time, it can also increase the living comfort and happiness index of residents, so dust monitoring is very necessary. In this paper, the research status, necessity and development benefits of urban construction site dust monitoring are expounded, then sort out the key points of dust monitoring technology, and give some suggestions to the possible problems in the existing technology to ensure the smooth implementation of dust monitoring. And put forward the proposal with the dust treatment and control from construction unit, construction unit and supervision unit three aspects to help reduce the construction of dust pollution.

Direct foliar acquisition of desert dust phosphorus fertilizes forest trees despite reducing photosynthesis.

Phosphorus (P) availability to forest trees is often limited by local soil conditions that increase its fixation to soil minerals. In certain regions, atmospheric-P inputs can compensate for low soil-P availability. Among atmospheric-P sources, desert dust is the most dominant. However, the effects of desert dust on P nutrition and its uptake mechanisms by forest trees are currently unknown. We hypothesized that forest trees that naturally grow on P-poor soils or soils with high soil-P fixation capacity can acquire P from desert dust deposited on their leaves via direct foliar uptake, bypassing the soil, thus promoting tree growth and productivity. We performed a controlled greenhouse experiment with three forest tree species: Palestine Oak (Quercus calliprinos) and Carob (Ceratonia siliqua), native to the NE edge of the Saharan desert, and Brazilian peppertree (Schinus terebinthifolius), native to the Atlantic Forest in Brazil, which is located on the western part of the trans-Atlantic Saharan dust route. To simulate natural dust deposition events, the trees had desert dust applied directly upon their foliage and were monitored for growth and final biomass, P levels, leaf surface pH and the rate of photosynthesis. The dust treatment increased the P concentration significantly by 33-37% in Ceratonia and Schinus trees. On the other hand, trees that received the dust displayed a 17-58% reduction in biomass, probably related to particle coverage of the leaf surface that inhibited photosynthesis by 17-30%. Overall, our findings show that direct P uptake from desert dust can be an alternative P uptake pathway for multiple tree species under P-deficient conditions, with implications for forest trees' P economy.

A novel process for the treatment of steelmaking converter dust: Selective leaching and recovery of zinc sulfate and synthesis of iron oxides@HTCC photocatalysts by carbonizing carbohydrates

A large amount of converter dust (CD) is generated annually, posing serious environmental problems due to its zinc content. Moreover, zinc mainly exists in the form of inert ZnFe2O4 in CD, which negatively affects the leaching efficiency of zinc. On the other hand, the photocatalytic activity of hydrothermal carbonation carbon (HTCC) is restricted by its wide bandgap, poor charge-transfer ability, and inconvenience of recycling. This work presents an oxygen pressure leaching method to selectively leach Zn from CD. In this process, not only the decomposition of ZnFe2O4 is effectively promoted to increase zinc recovery, but also Fe2+ in the solution is skillfully oxidized and hydrolyzed to solid Fe(OH)SO4. Under the optimum conditions, the leaching efficiency of zinc reached 98.8%, and 86.3% of iron remained in the leach residue, realizing the one-step separation of zinc and iron. Furthermore, the leach residue was successfully applied to synthesize a magnetically recyclable iron oxides@HTCC composite photocatalyst.

The behavior of separation and enrichment of valuable metals during the synergistic processing of metallurgical dust and sludge via roasting in rotary kiln

The generation of ironmaking and steelmaking dust and sludge exceeds 100 million tons annually, and stacking critically pollutes the environment. The joint treatment of such wastes for recycling metals is a promising approach to resolving these problems. This study focused on the separation and enrichment of metals during the synergistic processing of blast furnace dust, electric arc furnace dust, and steel pickling sludge in a rotary kiln at high temperature. Research results indicate that Na2O, K2O, Rb2O, Cu2O, ZnO, CdO, PbO, Bi2O3, and Sb2O3 may be separated during roasting. Under optimized Zn removal conditions of 30 min roasting time and 1373 K roasting temperature, the removal percentages of Sn, Sb and Cu reach 91.9%, 97.2%, and 72.4%, respectively, while Bi, Rb and Cd are removed almost entirely from the mixture of dust and sludge. The removed metals condense before the flue gas outlet (330 K) and are concentrated in the Zn-rich powder. The concentrations of Sn, Sb, Bi, Rb, and Cd in the Zn-rich powder were 5–7 times those in the mixture. The synergistic treatment of metallurgical dust and sludge may facilitate the efficient separation and enrichment of certain valuable metals, and the methods may be extended to jointly processing the other solid wastes; however, HCl gas formation may complicate gas cleaning.

Study on Crust-Shaped Dust Suppressant in Non-Disturbance Area of Open-Pit Coal Mine-A Case Study.

Dust pollution in open-pit coal mines severely restricts the green development of mines. Therefore, dust control has become an important requirement for the sustainable development of the mining industry. With the goal of dust pollution prevention and control in open-pit coal mines, this paper puts forward the concept of a non-disturbance area of an open-pit coal mine. It clarifies the characteristics of dust generation, the coverage area, and the dust particle size distribution characteristics of the non-disturbance area. Taking the dust control at the dump site as an example, the study comprehensively utilizes indoor tests and field tests to develop a dust suppressant for the dump site and determine its dust suppression efficiency and effective service cycle. The results show that the D10, D50, and D90 particle sizes of dust in the non-disturbance area are smaller than those in the disturbance area, and the difference in particle size of D90 is the most obvious. Gelatinized starch and non-ionic polyacrylamide, as the main components of the dust suppressant, can effectively reduce dust pollution in the dump; the optimal concentration is 1.0%, and the dust suppression service cycle is more than one month. The developed dust suppressant does not contain corrosive, toxic, or heavy metal elements. Although the application of a dust suppressant will cause plant growth to lag, it does not affect plant health. The research findings serve as a reference for the zoning treatment of dust in open-pit mines.

Substantiation of Practical Recommendations on the Organization of Optimal Modes of Preliminary Heat Treatment and Combustion of Coal in a Pulverized State

Based on the data on the reactivity of coal, a calculated justification of the requirements for the organization of its preparation and combustion processes was carried out, taking into account the initial quality and operating modes of the preparation systems and combustion devices of power steam boilers. The relationship between such operating parameters of the device for preliminary heat treatment of coal as the size of pulverized coal particles, temperature and duration of treatment with the quality of the source fuel has been established in order to ensure stable ignition and completeness of burnout of the products of thermochemical transformation of coal in the conditions of the furnace chamber of the boiler unit. The results of the cycle of analytical studies are summarized and brought to the level of engineering methodology (in the form of a nomogram), which allows determining the optimal values of temperature and time of the process of preliminary heat treatment of coal before combustion in the furnace chamber of a steam boiler based on the known characteristics of the initial fuel (reactivity and particle size). The found operating parameters of the device for preliminary heat treatment of coal ensure the performance of verification (thermal) and design calculations of real fuel-using installations, for example, fuel-free kindling and dust preparation systems. It is established that the most optimal mode of preliminary heat treatment of brown Kansk-Achinsk coals polyfraction, in terms of the efficiency of ignition and combustion of heat treatment products, is 800–850°C with a processing time of 0.6–1.2 s. The results of the calculated studies were confirmed during experimental work on a special laboratory stand, which provides a mode of preliminary heat treatment of coal in a pulverized state in a wide temperature range and afterburning of dust and gaseous heat treatment products under various conditions.

Field experimental study on comprehensive dust control technology in fully mechanized caving face of extra thick coal seam

In order to solve the dust treatment problem of the coal Permian extra thick coal seam mined by Tashan Coal Mine, the comprehensive dust treatment technology research was carried out with the 8106 comprehensive discharge face and 8210 comprehensive discharge face of Tashan Coal Mine as the geological background, and the four aspects of coal seam water injection process, determination of water injection parameters, inspection of water injection and dust reduction effect and application promotion prospects were analyzed and studied.

Leaching Characteristics of Heavy Metals in the Baghouse Filter Dust from Direct-Fired Thermal Desorption of Contaminated Soil.

After thermal desorption, the total amount of heavy metals (HMs) is enriched in baghouse filter dust. To further understand the related environmental impact, the leaching characteristics under various conditions must be explored. Therefore, this study aimed to examine the leaching characteristics of seven HMs in the dust generated in the direct-fired thermal desorption process and to compare the differences in heavy metal leaching characteristics in the soil before and after thermal desorption. The leaching characteristics and bioaccessibility of seven HMs-arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)-were analyzed in dust and in soil before and after thermal desorption. The activity of HMs in dust was strong. Therefore, environmental effects and effects on human health should be considered in the treatment of soil and dust after thermal desorption.

Green and efficient recovery of valuable metals from by-products of zinc hydrometallurgy and reducing toxicity

Germanium-containing dust as an intermediate by-product in the process of zinc hydrometallurgy, which often contains a large number of heavy metal substances. Due to the constraints of economic benefits and process technology, green and efficient treatment of germanium-containing dust is always a great challenge. In this work, XRD, ICP-OES, XPS, SEM and other characterization methods were used to analyze the existing state and quantity of main substances in germanium-containing dust. It was found that the occurrence state of germanium was closely related to sphalerite. At the same time, longer reaction time would lead to continuous hydrolysis of silicate, which would eventually affect the recovery of zinc, germanium and lead and the fixation of toxic substances. Therefore, the ultrasonic enhanced ammonium persulfate oxidation process was proposed to control the waste of resources and environmental pollution caused by the accumulation of germanium-containing dust. The final results showed that more than 95% of zinc and 89% of germanium were efficiently recovered, and heavy metals such as arsenic and cadmium were fixed in the liquid, and then concentrated in the purification and impurity removal stage. The residue after reaction is high-grade lead sulfate residue, which can be returned to the lead smelting system for recycling. In summary, the ultrasonic-enhanced ammonium persulfate process eventually makes all substances in germanium-containing dust harmless and resource treatment.

Crushed amygdaloidal basalt rock and its effects on tomato production

Abstract
 Sustainable agriculture plays an important role in agricultural productivity, in which it seeks to reduce dependence on conventional synthetic fertilizers (imported from Europe) and promote the use of alternative, low-cost and environmentally friendly sources. An experiment was carried out in the municipality of Santa Maria, Rio Grande do Sul, Brazil, with the objective of evaluating the efficiency and agronomic viability of using a mineral product (amygdaloid basalt powder) as an agricultural input on tomato productivity Solanum lycopersicum. The experimental design used was randomized blocks with six treatments and four replications, at doses 0 (treatment 1 - control), 1.0 ton ha-1 of rock dust (treatment 2), 2.5-ton ha-1 of rock dust (treatment 3), 3.5-ton ha-1 of rock dust (treatment 4), 4.5-ton ha-1 of rock dust (treatment 5), and recommended fertilization for tomato 5-20-20 NPK (treatment 6 - standard). The treatments were applied in December 2018 and the transplant took place in February 2019. According to the conditions under which the experiment was submitted and analyzing the results obtained, it can be inferred that the application of 1-ton ha-1 of amygdaloidal basalt in the soil increased parameters such as root length, stem diameter, green and dry mass of shoots and roots, number of flowers/plants, number of fruits/plant and productivity in tomato Solanum lycopersicum. It is a viable, sustainable, and low-cost strategy that contributes to the achievement of the Sustainable Development Goal (SDG 2) and can be replicated in Brazil and worldwide.

Carbothermic Kinetics and Reaction Mechanism of Carbon-Containing Pellets: A Combined Treatment of Chromium-Containing Sludge and Zinc-Bearing Dust

Carbothermic Kinetics and Reaction Mechanism of Carbon-Containing Pellets: A Combined Treatment of Chromium-Containing Sludge and Zinc-Bearing Dust

Treatment of Soot and Dust in Biofuel Exhaust Gas by UFB Water Scrubber

Treatment of Soot and Dust in Biofuel Exhaust Gas by UFB Water Scrubber

Prediction of Dust Abatement Costs in Construction Demolition Projects

Dust pollution arising out of building demolition has serious health implications on workers, as well as the neighboring communities. Existing research has shown that regulatory and engineering control methods are the most popular for dust pollution control on demolition sites. Though engineering control methods are effective in suppressing dust pollution, they have enormous cost implications for demolition companies. Therefore, accurate prediction of dust treatment costs is an important element of the demolition planning process. However, very little information is available in the existing research about treatment costs. In addition, there has not been any attempt to develop a model which can accurately predict the cost of dust treatment during building demolition. To overcome this knowledge gap, a grey prediction model is built according to the information obtained from twenty previous demolition projects. The historical trend of demolition project cost is combined to establish the prediction model based on GM (1, 1), which can be used to obtain the dust treatment cost of a project with very high accuracy. To further improve the prediction accuracy, this paper also builds a Single Function Residual Identifiability (SFRI) model. The relative error between the actual and predicted dust treatment costs from 2013 to 2021 ranges from 0.003% to 0.077%. Through detailed assessment of various treatment measures using a case study, it was found that the results obtained by the prediction model are very close to the actual costs incurred, which verifies the accuracy of the proposed model.