Waste Mica Research Articles

Exploring waste mica as an alternative potassium source using a novel potassium solubilizing bacterium and rice residue in K deficient Alfisol

Exploring waste mica as an alternative potassium source using a novel potassium solubilizing bacterium and rice residue in K deficient Alfisol

All-natural, thermally conductive, flame-retardant electrical insulating lignocellulose-mica composite film fabricated via in-situ mineralization

Miniaturized, integrated, and functional electronic devices generate a large amount of heat accumulation during operation, which significantly affects the reliability, durability, and safety of electronic devices. In severe cases, it may even lead to fires. Therefore, the development of insulation composite materials with thermal conductivity and flame-retardant properties is particularly important. In this study, we propose an in-situ mineralization strategy to prepare insulation composite materials with thermal conductivity and flame-retardant properties. By dissolving and preparing a gel film, Al3+ and Zn2+ retained inside the lignocellulose are in situ mineralized to form Al(OH)3 and ZnO, and introducing inorganic blocks with high insulation performance (industrial waste mica tailings and synthetic mica). The prepared film has excellent tensile strength (117.4 MPa), low dielectric loss, high dielectric strength (83.8 kV mm−1), high insulation resistance, four times higher thermal conductivity than the unmineralized film, and excellent flame-retardant properties. Meanwhile, the environmental impact of the composite film is much lower than that of petrochemical-based plastic films and can easily degrade under natural conditions within 32 days. It is a composite material that meets the standards of the new electrical insulation field, and the in-situ mineralization strategy can also provide ideas for the preparation of high-performance lignocellulose-based materials.

Enriched soil amendments influenced soil fertility, herbage yield and bioactive principle of medicinal plant (Cassia angustifolia Vahl.) grown in two different soils

High cost of chemical fertilizers and poor nutrient content in conventional organic sources (manure, compost, charcoal etc.) can be addressed through development of enriched organic amendments. However, there is a need to evaluate enriched organic amendments as a potential alternative of chemical fertilizers. Therefore, an effort was made to prepare enriched organic amendments through blending distillation waste of aromatic plant biomass (DWB) with naturally available low-grade rock phosphate (RP) and waste mica (WM). Enrich compost (ENC) was produced from DWB in a natural composting process, blended with mineral powder, whereas biochar fortified mineral (BFM) was prepared by blending biochar, derived from DWB through hydrothermal reaction, with mineral powder. The main aims of the present study were to investigate the impacts of ENC and BFM applications on soil properties, and herbage yield and quality of a medicinal herb Senna (Cassia angustifolia Vahl.). The performances of ENC and BFM at two different rates (2.5 and 5 t ha−1) were compared with the application of conventional farmyard manure (FYM, 5 t ha−1) and chemical fertilizers (CF, NPK 60-40-20 kg ha−1) in two different soils in a pot experiment. Both, ENC and EBC improved soil quality and fertility by increasing soil organic carbon, available nutrients, microbial biomass and enzyme activity. The ENC and BFM increased total herbage yields by 21 and 16.3 % compared to FYM. In both soils, the CF treatment produced the maximum dry herbage yields (32.7–37.4 g pot−1), which however were comparable to ENC (31.9–33.7 g pot−1) and BFM (30.7–35.1 g pot−1) treatments. Bioactive compound (sennoside) production in senna was significantly improved by ENC and BFM compared to CF. The present study indicates that ENC and BFM could not only help to overcome the limitation of conventional FYM, but also have the potentials to substitute costly chemical fertilizers, particularly in medicinal plant cultivation.

Effects of latex type and processed-mica waste loading on the structural and thermo-physical properties of natural rubber latex foam composites

Mica waste, a type of commercial waste produced in bulk quantities by the mica mining industry, was processed and added to Natural Rubber Latex Foams (NRLF) made of centrifuged and creamed latex. Following the Dunlop method, NRLF composites with various Processed Mica Waste (PMW) loadings (0, 2, 4, 6, 8, and 10 Phr) were prepared, and the thermo-physical characteristics were compared. Thermal conductivity, electrical resistivity of NRLF against the latex type and mica loading were compared for the first time. NRLFs prepared using creamed latex exhibit 33 and 50 μm (width and height) cell diameter, 3 ibf hardness, 281 % swelling index improvements and 0.05 Wm−1K−1 thermal conductivity, and 1 °C glass transition temperature (Tg) reductions than centrifuged NRLF and indistinguishable electrical resistivity. With the addition of mica (0–10 Phr), both NRLF types showed a similar ascending trend in hardness (42 ibf), water absorption (16 %), Tg (7 °C), thermal conductivity (0.54 Wm−1K−1), electrical resistivity (69 × 103 Ω m) with decreasing gel time (3 min) and swelling index (550 %). The key objective of this research was to prepare PMW-filled NRLF and compare structural, electrical and thermo-physical properties, for the first time, against mica content and latex type.

An all-natural, bioinspired, biodegradable electrical insulating composite based on lignocellulose and mica tailings

The rapid development of modern electrical engineering puts forward urgent demand for high-performance electrical insulating materials. In this study, inspired by the layered structure of natural nacre, we present a novel biomimetic composite insulating film (referred to as M/C film) that is derived from agricultural waste corncobs and industrial waste mica tailings through a sol-gel-film transformation process. The novel insulating film has excellent tensile strength (94 MPa), high dielectric strength (68 kV mm−1), low dielectric loss, good heat resistance (T0 = 235 °C), and excellent UV shielding properties. Meanwhile, the M/C film presents environmental impacts much lower than those petrochemical-based plastic film as it can be 100 % recycled in a closed-loop recycling process and easily biodegraded in the environment (lignocellulose goes back to the carbon cycle and the mica return to the geological cycle). It is a potential alternative for petrochemical plastics and provides a possible way to utilize agricultural waste and mica tailings.

Development of exfoliated mica waste/natural rubber composites by latex stage mixing

ABSTRACT Raw mica powder may not show better physico-mechanical properties in rubber owing to its large particle sizes and low degree of surface activeness. Here, mica waste; a green filler was modified by partially exfoliating before incorporating it into natural rubber (NR). The latex stage mixing was conducted to incorporate different loadings of exfoliated mica waste (eWM). The incorporation of eWM had no significant effect on cure and scorch time. The reduction of viscosities indicated better processability of the compounds. The overall improvement of moduli, tensile, abrasion resistance, and cross-link densities supported by SEM and TGA data suggested improved rubber–filler interactions.

Low-grade silicate minerals as value-added natural potash fertilizer in deeply weathered tropical soil

High price of chemical potassium (K) fertilizers together with low K use efficiency in weathered tropical soils necessitates the exploration of alternative K fertilizer sources. Effectiveness of low-grade silicate mineral powders (SMP) as a natural K fertilizer in a highly weathered tropical soil was evaluated in this study via laboratory and pot experiments by growing oat (Avena sativa L) and palmarosa (Cymbopogon martini var. motia). Five SMP materials (two mica, one feldspar and two greensand) were obtained from quarry mining sites across India. The total K content in the SMP followed the order: feldspar (12.3%) > waste mica (5.98–8.03%) > greensand (3.77–4.46%). The amount of K released from SMP by chemical extractants was in the following order: water < 0.01 M citric acid < 1 M ammonium acetate < 1 M nitric acid, which indicated that SMP was a slow-release K source. Of the five SMP materials, one waste mica, the feldspar and one greensand were included in the plant growth experiments based on their high K contents. Water and 0.01 M citric acid extractable K from SMP showed the best correlation with K uptake by plants. Compared to feldspar (19.7–22.5%) and greensand (5.4–7.5%), the K recovery from waste mica (39.3–42.5%) was notably higher in both palmarosa and oat. Soil K pool was significantly recharged with waste mica application as evident from higher exchangeable and non–exchangeable K in soil than chemical fertilizer treatment. Application of SMP, particularly waste mica and feldspar, also increased the soil pH and cation exchange capacity by releasing basic cations and improving their retention in the tropical soil. By using low-grade SMP in agriculture, it is thus possible to achieve green recycling of mining wastes as K fertilizer while improving crop production and amending poor quality soils.

Pollution and health risk assessment of mine tailings contaminated soils in India from toxic elements with statistical approaches

The rapid mining activities of mica mines in Giridih district, India, have led to toxic metal pollution of agricultural soil. This is a key concern for environmental risk and human health. 63 top soil samples were collected at a distance of 10 m (Zone 1), 50 m (Zone 2), and 100 m (Zone 3) from near 21 mica mines with agriculture fields. The mean concentration of total and bio-available toxic elements (TEs - Cr, Ni, Pb, Cu, Zn, and Cd) was higher in zone 1 across three zones. The Positive matrix factorization model (PMF) and Pearson Correlation analysis were used to identify waste mica soils with TEs. Based on PMF results, Ni, Cr, Cd, and Pb were the most promising pollutants and carried higher environmental risks than the other TEs. Using the self-organizing map (SOM), zone 1 was identified as a high-potential source of TEs. Soil quality indexes for TEs risk zone 1 were found to be higher across three zones. Based on the health risk index (HI), children are more adversely affected than adults. Monte Carlo simulations (MCS) model and sensitivity analysis of total carcinogenic risk (TCR), children were more affected by Cr and Ni than adults through ingestion exposure pathways. Finally, a geostatistical tool was developed to predict the spatial distribution patterns of TEs contributed by mica mines. In a probabilistic assessment of all populations, non-carcinogenic risks appeared to be negligible. The fact that there is a TCR can't be ignored, and children are more likely to develop it than adults. Mica mines with TEs contamination were found to be the most significant anthropogenic contributor to health risks based on source-oriented risk assessment.

Temporal Dynamics of Potassium Release from Waste Mica as Influenced by Potassium Mobilizing Bacteria

Potassium mobilizing bacteria (KMB) strains have been isolated from waste mica mines in the Giridih district of Jharkhand, India, using Alexandrov media. These isolates were evaluated for their potential to dissolve water soluble-K from waste mica (muscovite and biotite). Identity was confirmed based on sequencing of 16S rDNA region of those isolates showing promising water soluble-K dissolving capacity. Strains were found to be different isolates of Bacillus cereus, two unconfirmed Bacillus species (strain- 6SB1 and GG6), and one each of B. velezensis and Paraburkholderia kururiensis. Finally, the four most efficient KMB were selected based on their K-mobilizing capability. The K5B (B. cereus) isolate showed the highest K-solubilising capacity in both muscovite and biotite enriched medium. Soil incubation study was conducted using soils of Giridih (Alfisol) with three gradient concentrations of both waste mica tailings and K-solubilising capacity of four KMB isolates (B. cereus, strain- K5B, K6, K15; and Bacillus sp. GG6- K12) were measured at 4, 7, 14 and 21 days intervals. The K release dynamics in incubated soils indicated that potassium was released from both types of micas to significantly higher water-soluble K (WS-K) and exchangeable K (Ex-K) pools due to the inoculation of KMB isolates. Apart from potassium solubilization, B. cereus strain K5B and Bacillus sp. GG6 showed capabilities to produce indole acetic acid (IAA) and gibberellic acid (GA). These results suggested that a combination of KMB strain and powdered mica tailings could be a suitable alternative to commercial chemical fertilizers and maintain soil nutrient status for plant uptake.

Physical properties of natural rubber latex foams produced with processed mica waste powder and creamed natural rubber latex

Incorporation of finely powdered mica waste into natural rubber latex processed into foam rubber, consuming a minimum amount of energy could contribute to progress towards a greener environment. In this study, mica waste generated in the mining industry was finely powdered and incorporated into creamed natural rubber latex which is an alternative form of concentrated latex manufactured using a green process known as the creaming process. Finely powdered processed mica waste (PMW) was added as a filler into latex varying the loading from 0 to 10 pphr at 2 pphr intervals. The latex foam was then converted into a vulcanized natural rubber latex foam (NRLF). Effects of mica loading on certain properties of the foam rubber produced from creamed natural rubber latex were studied. It was found that the density and hardness of the mica powder incorporated foam rubber increased with increasing filler loading. Fourier transformed infrared spectroscopy (FTIR) studies confirmed that no structural changes occurred in natural rubber due to the addition of PMW. The overall results of the study showed the potential of utilization of mica waste and creamed natural rubber latex to manufacture greener natural rubber foam composites in cottage-level foam manufacturing industries.

Effect of metal fractions on rice grain metal uptake and biological parameters in mica mines waste contaminated soils

Heavy metals from mica waste not only deteriorate the soil quality but also results in the uptake of metals in the crop. The present investigation was conducted to evaluate the effects of different fractions of metals on the uptake in rice, soil microbial and biochemical properties in mica waste-contaminated soils of Jharkhand, India. From each active mine, soil samples were randomly collected at distances of < 50 m (zone 1), 50–100 m (zone 2), and >100 m (zone 3). Sequential metal extraction was used to determine the fractions of different metals (nickel (Ni), cadmium (Cd), chromium (Cr) and lead (Pb)) including water-soluble (Ws) and exchangeable metals (Ex), carbonate-bound metals (CBD), Fe/Mn oxide (OXD) bound metals, organically bound metals (ORG), and residues (RS). The Ni, Cr, Cd and Pb in rice grain were 0.83±0.41, 0.41±0.19, 0.21±0.14 and 0.17±0.08 mg/kg respectively. From the variable importance plot of the random forest (RF) algorithm, the Ws fraction of Ni, Cr and Cd and Ex fraction of Pb was the most important predictor for rice grain metal content. Further, the partial dependence plots (PDP) give us an insight into the role of the two most important metal fractions on rice grain metal content. The microbial and enzyme activity was significantly and negatively correlated with Ws and Ex metal fractions, indicating that water-soluble and exchangeable fractions exert a strong inhibitory effect on the soil microbiological parameters and enzyme activities.

Domas (Dompet Masker) Sebagai Inovasi Pemanfaatan Limbah Plastik dan Kain Perca Bermotif Keanekaragaman Indonesia di Era Pandemic COVID-19

Background: One of the efforts funded by Dikti in implementing the Student Creativity Program in the field of entrepreneurship gave us the opportunity to produce a Dompet Mask (DOMAS) product made using modified patchwork waste and mica polyvinyl chloride plastic waste with a thickness of 0.4 mm. The tools and materials we use are very affordable during this COVID-19 pandemic. Objective: Provide quality Domas innovation, practical, and safety of the waste material. Providing business opportunities through student creativity programs. Marketing DOMAS offline and online throughout Indonesia by actively promoting and improving the quality of products handmade. Methods: The implementation of activities is carried out outside the network (offline) and within the network (online). The activity was carried out at the production house located at Jatisawit Housing, Sleman, Yogyakarta. The production period starts on 08/08/2021 until 12/09/2021. Product marketing online and offline. Result: The selling price per unit is Rp. 20,000. For five weeks producing 250 DOMAS. DOMAS sales resulted in a profit of Rp. 3,000,000 with a cost of Rp. 1,549,080, a profit of Rp. 418,200 was obtained. The number of DOMAS that have been sold is 150 units. The profit per DOMAS unit is IDR 2,788. The original price per wallet is Rp. 17,212. Conclusion: The "DOMAS" mask wallet is a new breakthrough in the era of the COVID-19 pandemic. DOMAS has the advantage of being able to store clean and dirty masks in one place. In addition to the unique and attractive design of the mask, the materials used are also environmentally friendly, made from plastic waste mica PVC and waste batik patchwork with the motifs of the diversity of the archipelago.

A comparative study on mica waste‐filled natural rubber foam composites made out of creamed and centrifuged latex

AbstractA comparative study on processed mica waste (PMW) filled natural rubber latex foams (NRLF) made out of centrifuged latex and creamed latex was conducted. The morphological, mechanical, and degradability properties of the composites were studied. The PMW was incorporated at 0, 2, 4, 6, 8, and 10 phr loading. Morphological studies revealed that both types of composites possess open‐cell structures. However, creamed latex based foam rubber composites showed foam structures with much larger cell sizes. PMW loading showed similar influences on the properties of the foam composites, irrespective of the latex type used. Increasing filler loading increases tensile strength, modulus at 100% elongation, tear strength, compression set, shrinkage, biodegradability, and antibacterial properties and reduces elongation at break and extractable protein content while offering a slightly dark color to the composites. It was also found that the creamed latex based foam rubber exhibits lesser extractable protein content and slightly inferior properties in tensile strength, shrinkage properties and color compared to centrifuged latex based foam rubber. However, it was shown that type of latex does not influence biodegradability, antibacterial properties, and color retention. Thermogravimetric analysis results confirmed the thermal resistance and reinforcing ability of mica in both NRLF composites.

Waste mica as filler for natural rubber latex foam composites

Waste mica as filler for natural rubber latex foam composites

Bio-activation of waste mica through potassium solubilizing bacteria and rice residue

This article aims to demonstrate the increase in availability of potassium (K) from mica through bio-activation using different strains of potassium solubilizing bacteria (KSB) and rice residue incorporation and comparing it with standard K-fertilizer i.e. muriate of potash (MOP). The effects of mica, rice residue and KSB on wheat biomass yield, K uptake and available K in soil were assessed through a pot culture study at research farm of ICAR-Indian Agricultural Research Institute, New Delhi (2019). Results reveal that mica application @ 50 and 100 mg/kg soil significantly improved the biomass yield and K uptake by wheat as compared to treatments without mica application. Rice residue incorporation @ 2 g/kg soil had significant role in improvement of biomass yield, K uptake by wheat and available K in soil as compared to no residue treatments. Amongst the two isolated strains of KSB (JHKSB1 and JHKSB4) and one standard strain (Bacillus sp.), all were found equally effective in improving K availability from mica to the wheat crop. Mica, bio-activated via rice residue and KSB was able to improve relative agronomic efficiency and per cent K recovery from soil but it was not as effective as MOP. Thus, inherent K content in mica may be available to crops partly after bio-activation and it can be applied in conjunction with MOP for meeting the K requirement of the crop.

On the utilization of mica waste: The pore-fluid chemistry of mica soils and its implication for erosion susceptibility

Soil is a vital resource which is limited in availability and must be adequately managed for sustainable development. Despite the importance of soil and its limited availability, a huge amount of soil is classified as waste. As one of the world’s largest soil waste generators, the mining industry must transition to a circular economy model to meet sustainability requirements. As a readily available, large-volume waste material (about 10 million tonnes each year), waste mica has been considered for re-use as an alternative soil potassium source for plants, as landscaping material etc. One of the problems with mica waste is its susceptibility to erosion. To use mica as an agricultural or landscaping material, it is therefore important to understand the erodibility of mica and how its erodibility can be reduced. This study presents an experimental campaign to characterize mica erosion susceptibility. Mica particle-to-particle interaction forces and their effect on the macroscopic material behaviour were systematically investigated by changing pore fluid pH and ionic concentration. Sedimentation and liquid limit tests were first carried out to inform a conceptual model of the mica fabric. Triplets of 12 mica samples, compacted at different water contents and with different pore chemistry, were tested for erosion susceptibility using a Jet Erosion Test (JET) apparatus. The particle configuration of mica samples consistently varied with the pore water chemistry, regardless of whether the samples being tested were suspension sediments or compacted samples. For mica samples formed with neutral water at low ionic concentration, the particles are in a dispersed configuration. This implies a poor mechanical behaviour and high erosion susceptibility, as particles are eroded one by one. For porewater samples formed with an increased ionic strength or within the acidic pH range, particles tend to cluster together and organize in a non-dispersed configuration. This results in an improved mechanical behaviour and less erosion susceptibility, as group of particles must be eroded as opposed to individual ones. Similarly, the Jet erosion test results reinforced these observations showing that mica erodibility varies with porewater chemistry. Considering that mica erodibility varies with pore fluid chemistry and mica waste derived from mining operations are often slightly acidic, this paper paves the way for tailored assessments of individual mica waste materials to determine the appropriateness of their use.

Combined application of mica waste and Bacillus pseudomycoides as a potassium solubilizing bio-fertilizer reduced the dose of potassium fertilizer in tea-growing soil

ABSTRACT Potassium-solubilizing bacteria (KSB) are often used in the field of vegetable and horticultural crops. In this study, a strain of Bacillus pseudomycoides was used as the KSB strain and different combinations of muriate of potash (MoP) and mica waste (MW) along with that strain were applied in soil to evaluate its effect on exchangeable K content in soil and yield of tea shoots. The objective of this experiment was to evaluate the possibility of applying an indigenous KSB strain and MW combination for reducing doses of MoP during cultivation of perennial crops like tea. The study over two consecutive years revealed that cumulative tea production of some of the applied treatments was significantly higher than that of recommended MoP treatment. Application of KSB and MW in the first split instead of MoP recorded higher exchangeable K content in soil during August to October, especially in the second year of the study. The study confirmed B. pseudomycoides can be used as a KSB biofertilizer in soil and application of MW and KSB combined replacing MoP in the first split could be economical as well as improving K use-efficiency in soil and increased yield and K-uptake by the plants.

Repurposing distillation waste biomass and low-value mineral resources through biochar-mineral-complex for sustainable production of high-value medicinal plants and soil quality improvement

High cost of synthetic fertilizers and their hazardous effects catapult the exploration of alternative nutrient formulations and soil amendments. This study aimed to synthesize a novel biochar-mineral-complex (BMC), and evaluate its nutrient supplying and soil improvement performances. In a hydrothermal reaction, the BMC was prepared using a biochar derived from distillation waste of Lemongrass (Cymbopogon flexuosus) and farmyard manure, for the first time via fortification with low-grade rock phosphate and waste mica. The BMC showed improved physico-chemical properties and nutrient availability than the pristine biochar. When applied to a deeply weathered acidic soil, the BMC significantly (P < 0.05) improved the herbage and bioactive compound (sennoside) yields of a medicinal plant (senna; Cassia angustifolia Vahl.) compared to the pristine biochar, farmyard manure, vermicompost, and chemical fertilizers. The BMC also improved the soil quality by increasing nutrient and carbon contents, and microbial activities. Soil quality improvement facilitated greater nutrient uptake in senna plants under BMC compared to the pristine biochar, and conventional organic and chemical fertilizer treatments. This study thus encourages the development of BMC formulations not only to overcome the limitation of sole biochar application to soils, but also to phaseout chemical fertilizers in agriculture. Moreover, BMC could bestow resilience and sustainability to crop production via value-added recycling of waste biomass and low-grade mineral resources.

A novel application of Linz-Donawitz Slag for potash recovery from waste mica scrap using chlorination roasting coupled water leaching process

ABSTRACT The present article reports a novel process for the recovery of potash values from mica scrap (K2O 8.72%) using Linz-Donawitz Slag (LDS) and NaCl. Acid leaching of ground mica powder suggests a maximum of 22% potassium extraction. The roasting coupled water leaching process, using a mixture of LDS and NaCl, could extract a maximum of 93% potash at 900°C for 30 min roasting. The roasting temperature is the key parameter during the extraction process. The possible potash recovery mechanism is discussed on the basis of XRD, EPMA, and SEM-EDS studies of various feed and processed products.

Chlorination roasting-coupled water leaching process for potash recovery from waste mica scrap using dry marble sludge powder and sodium chloride

The present paper reports the effective utilization of marble sludge powder (MSP) for the recovery of potash values from waste mica scrap using chlorination roasting-water leaching method. Characterization studies indicated the presence of dolomite as the major mineral phase in MSP, whereas muscovite and quartz were observed in the mica sample. The acid leaching studies suggest a maximum of 22% potash recovery under conditions: 4 M H2SO4 acid, particle size of ∼100 µm, stirring speed of 600 r/min, leaching temperature of 75°C, and leaching time of 90 min. The chlorination roasting-water leaching process was adopted to achieve the lowest level of 80%–90% potash recovery. The optimum conditions for the recovery of ∼93% potash from mica (∼8.6wt% K2O) requires 900°C roasting temperature, 30 min roasting time, and 1:1:0.75 mass ratio of mica: MSP: NaCl. The roasting temperature and amount of NaCl are found to be the most important factors for the recovery process. The reaction mechanism suggests the formation of different mineral phases, including sylvite (KCl), wollastonite, kyanite, and enstatite, during roasting, which were confirmed by X-ray diffraction (XRD) analyses and scanning electron microscopy (SEM) morphologies. The MSP-blended NaCl additive is more effective for potash recovery compared with the other reported commercial roasting additives.