Influence Of Kaolin Research Articles

Influence of kaolin and red clay on ceramic specimen properties when galvanic sludge is incorporated to encapsulate heavy metals

This study presented the influence of two types of clay: kaolin (Kao) and red clay (RC) on the chemical and physical properties of ceramic specimens when galvanic sludge (GS) is incorporated to encapsulate heavy metals. Samples were obtained of GS from the industrial district of Manaus – Amazonas State, Brazil, and kaolin (Kao), and red clay (RC) from the Central Amazon. A fourth sample was prepared by mixing GS, Kao, and RC in the ratio 1:1:8 (GS + Kao + RC). This mixture was ground, and ceramic specimens were prepared, and heat treated at 950 °C and 1200 °C for three hours for phase detection, compressive strength, leaching of Fe, Ni and Cr metals and life cycle assessment. Galvanic sludge, Kao, and RC were also, and heat treated to at 950 °C and 1200 °C for three hours, obtaining GS950, GS1200, Kao950, Kao1200, RC950, and RC1200. The samples were submitted to XRF, XRD, Rietveld refinement, Mössbauer spectroscopy, TG/DTG/DSC, and SEM. The results show that the formation of nickel oxide and a spinel solid solution of the type Fe3+{Fe1-y3+,Fe1-x2+,Nix2+,Cry3+}O4 (in which [] = tetrahedral site, {} octahedral site) occurs in GS1200, which is caused by sulfate decomposition to SO2. At 1200 °C, heavy metals are encapsulated, forming other phases such as nickel silicate and hematite. Life cycle assessment was used to verify the sustainability and value of GS in clay for making bricks, and it indicated that the production of ceramics is feasible, reduces the use of clays, and is sustainable.

Interactions between clay minerals, bacteria growth and urease activity on biocementation of soils

Biocementation is a low carbon footprint soil improvement technique alternative to the use of hydraulic binders such as cement, mainly applied in sandy soils due to the need for vital room for bacteria and easy access for nutrient transport to feed them. This treatment is not suitable for natural clayey soils, however pore clogging caused by the presence of clay in low percentages may not be a problem, and clay minerals can be beneficial to increase the area for bacteria to attach and therefore to precipitate larger quantities of biocement. In addition, clay minerals can also have a positive influence on bacteria activity itself, and this is the novelty of this investigation. The influence of kaolin and bentonite clays on biocementation using Sporosarcina pasteurii was measured by (i) the amount of calcium carbonate precipitated in sandy soil prepared with known percentages of the two clays (1%, 5%, 10% and 20% in dry sand mass), relating it with unconfined compression strength, and (ii) evaluating bacteria growth and urease activity in liquid media with 1% and 5% of each clay. The best enhancement of biocementation was found for kaolin percentage between 5% and 10% and for 5% of bentonite, considering as reference the case where no clay was added. These relatively small percentages were linked to physical aspects related with the room occupied by the clay minerals causing dispersion of the precipitate in the clay matrix, although the presence of clay in the fluids of soil voids could contribute positively for bacteria growth and long-term survival. These results confirm that biocementation treatment may be effective on soils with relatively small clay percentages and opens the possibility that clay can be used in controlled fixed amounts to improve the efficiency of this treatment in clean sands.

Effect of M-resin-based Stabilizer on the Performance of SBS Modified Asphalt

Industrial solid waste M-resin (MR) contains high sulfur content which was difficult to be comprehensively utilized. According to the vulcanization reaction mechanism, MR was used as vulcanizing agent, nano zinc oxide (ZnO) as an activator, tetramethyl thiuram disulfide (TMTD) as an accelerator to produce M-resin-based stabilizer. MR (0.5, 1, 1.5, 2, 2.5), ZnO (0.1, 0.2, 0.3, 0.4, 0.5) and TMTD (0.06, 0.08, 0.1, 0.12, 0.14) were mixed with different contents, a three-factor and five-level orthogonal experiment was designed to test the penetration, ductility, softening point and 48 h softening point difference of SBS modified asphalt. Based on the four indexes, the basic formula of the stabilizer was obtained. The influence of kaolin, an auxiliary material, on the thermal stability was compared, and the formula were optimized, the appropriate dosage was determined. The microscopic morphology of the modified asphalt and SBS developmental fineness was analyzed with the fluorescent microscopy technology, and the SBS developmental fineness was studied with the generated binary graph and skeleton graph. DSR test was carried out to detect rheological properties of modified asphalt with different dosages of MR-based stabilizes. The results show that MR can significantly improve the thermal storage stability of modified asphalt. The ratio of MR:TMTD:ZnO:Kaolin is 1.5:0.5:0.08:12, and the appropriate dosage is 1.02 %. The stabilizer can reduce the 48 h softening point difference 33.6 ℃, increase the softening point 13.6 ℃, decrease the penetration degree 9.7 mm, but it has little effect on 5 ℃ ductility index. The microscopic images show that a cavity two-phase continuous network structure is formed inside the modified asphalt under the appropriate dosage of M-resin-based stabilizer. The SBS developmental fineness is 2.36 μm, and the uniformity is good. DSR test also shows that stabilizer can effectively improve the high temperature performance of SBS modified asphalt.

Influence of kaolin and dolomite as filler on bond strength of polyurethane coated reinforcement concrete

This study deals with the bond performance of polyurethane coating filled by kaolin and dolomite. The ratio of fillers and polyurethane paints varied from 1:5 to 5:5. The effect of fillers on bond strength of coated steel bar on concrete was experimentally studied. FTIR, XRD, SEM, Coating Thickness and Bond Strength also carried out for better understanding of coating behaviour on mechanical properties of concrete and steel reinforcement. The best performance showed on pullout test by the 4:5 wt% of kaolin filler on polyurethane (PUK40). All dolomite filled polyurethane coatings (PUD10–PUD50) does not exhibit its good bond strength.

Influence of kaolin and coal fly ash addition on biomass ash deposition in an entrained flow reactor

The ash deposition behavior when firing different biomass (pulverized wheat straw, wood, bark, and leaves), with and without K-capture additives (kaolin and coal fly ash) was investigated through combustion experiments in the DTU (Technical University of Denmark) entrained flow reactor (EFR). In terms of deposit formation, the K- and Cl-rich Danish wheat straw proved to be the most problematic fuel, while milled wood pellets, leaves, and bark had significantly lower deposition propensities. Kaolin and two types of coal fly ash (Al- and Si-rich) were used as K-capture additives, and the results showed that with a fuel-K/additive-Al molar ratio of 1.0, the deposition propensity of wheat straw combustion was significantly reduced. However, the deposition propensity of the combustion of milled wood pellets did not change significantly with the addition of additives. ICP-elemental analysis of the deposits and fly ash samples showed that the water-soluble K content in the deposits and fly ash was significantly reduced for both wheat straw and wood pellet combustion. In comparison with the data from previous experiments, where pure K-salt reacted with solid additives, kaolin captured KOH more effectively than real biomass combustion. For coal fly ash, an opposite tendency was observed, i.e., it captured K more effectively under real biomass combustion conditions than under pure KOH reaction conditions.

Influence of Kaolin and Silica on some Refractory Properties of Pingell, Zircon Sand

100kg of zircon sand raw material was obtained from Pingell, Toro Local Area of Bauchi State while silica and kaolin were used as the additive materials in different proportions. The materials as received were wet and in large chunks, and was sun dried prior to crushing with Jaw crusher and sieved with the sieve of size 100 µ to obtain fine powder particles. Samples of various compositions were prepared from the powder particles of Zircon sand (X); Zircon sand and silica (Y); zircon sand, silica and kaolin (Z) and mixed together based on the experiment’s program with a predetermined amount of water in the mixer. Refractory brick test specimens were prepared by standard methods from samples A, B and C and subjected to refractory test such as apparent porosity, bulk density, cold crushing strength, linear shrinkage, thermal shock and refractoriness in order to evaluate the effects of adding silica and gypsum to Pingell zircon sand and investigate its suitability as raw material for refractory brick production and furnace linings. From the result obtained, the average porosity of X, Y and Z is 13.5, 18.3 and 21.6 % respectively while the respective bulk density are 3.2, 2.0 and 1.8 g/cm3. The values of the cold crushing strength for samples X, Y and Z are respectively 25.5, 23.4 and 18.8 MN/m2 but the firing shrinkage is 4.5, 5, and 6.5 %. Thermal shock resistance of 26, 20 and 22 cycles were obtained respectively for X, Y and Z. Refractoriness of 1600, 1580 and 1610 0C were obtained respectively for samples X, Y and Z. The porosity, firing shrinkage and refractoriness increased with increase in the addition of silica and kaolin to zircon sand whereas the bulk density, thermal shock resistance and cold crushing strength of zircon sand decreased with the addition of silica and kaolin but the addition of silica reduced the refractoriness of the zircon sand. The addition of silica and kaolin in the appropriate proportions improved the refractory properties of the zircon sand and hence will find applications in the production of refractory bricks and furnace lining.

Influence of Kaolin on the Formation and Sedimentation of Oil-Colloidal Particle Aggregates in Marine Environments

Li, J.; Xia, W.; Liu, L.; Zhang, M.; Zhao, B.; Liu, J.; Meng, M.; Zhao, Y., and Guo, J., 2020. Influence of kaolin on the formation and sedimentation of oil-colloidal particle aggregates in marine environments. Journal of Coastal Research, 36(3), 521–527. Coconut Creek (Florida), ISSN 0749-0208.Spilled oil in the marine environment is dispersed into droplets under the action of waves and currents, forming oil-colloidal particle aggregates (OcPAs) in the presence of clay particles in the ocean. Kaolin, which is a typical representative of clay particles, was investigated for its influence on the morphology and sedimentation characteristics of OcPAs in this work. Results have displayed that OcPAs exist mainly in the forms of single drop, double drops, and multiple drops, and their morphology is mainly affected by the turbulence intensity and kaolin concentration in seawater. Furthermore, it is observed that under medium- and high-turbulence intensity, the larger the fractal dimension of OcPAs is, the smaller the settling velocity becomes. The results suggest that the spilled oil can be removed from the sea surface by adding clay particles to promote the formation of OcPAs with large particle size and rapid settling velocity.

Study on the Effect of Additives on Na Migration of Zhundong Coal by Thermodynamic Calculation and Analysis

As a kind of low rank coal, ash of Zhundong coal contains relatively high content of alkali metals and alkaline earth metals, which leads to a strong slagging property. In this paper, the influence of kaolin and silica additive on the migration of alkali metal Na in Zhundong coal is studied by chemical thermodynamics calculation software, the results show that: The main form of sodium in the coal ash sample is Na2SO4. With the increase of temperature, the NaCl (g) in the ash sample begins to precipitate at 600 °C, and Na2SO4 changes to NaOH (g) and Na (g) at higher temperature. Both kaolin and silica can inhibit the release of sodium. After adding kaolin, NaAlSiO4 is the main form of solid Na in the ash, and after adding SiO2, Na2SiO3, Na2O2SiO2 and Na2O, 3SiO2 exist in the solid Na2SiO3.

Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

Influence of Kaolin on the Sintering of Glass Powder to Glass–Ceramics

Glass powder derived from a waste water flocculate was used to prepare sintered glass–ceramics. Different amounts of kaolin as a binder were mixed with the glass powder to form green bodies. The influence of the kaolin on the sintering, crystallization of the glass powder and on the microstructure of the obtained glass–ceramics has been investigated. DTA analysis suggests that the kaolin increases the crystallization temperature of the glass-kaolin mixtures. The results also show that the kaolin benefits reducing the sintering shrinkage of the green bodies. The kaolin does not lead to the change of crystalline phases in the sintered glass–ceramics. Instead, with an appropriate addition, the kaolin can provide reactive Al2O3 and SiO2 sources due to its decomposition favoring the crystal growth and improving the mechanical property of the sintered product.

Influence of anti-caking agent kaolin on film formation of ethylene–vinylacetate and carboxylated styrene–butadiene latex polymers

Colloidal stabilizers (e.g. PVOH) and anti-caking aids (e.g. kaolin) are commonly added during the spray drying of liquid latex dispersions to produce re-dispersible polymer powders for the drymix mortar industry. Here, the influence of kaolin and polyvinylalcohol on polymer film formation of an ethylene–vinylacetate (EVA) and a carboxylated styrene–butadiene (SB) latex dispersion in water and cement pore solution was investigated. Time-dependent ESEM analysis was conducted to analyze the progress of particle coalescence. The results show that both EVA and SB powders form a homogeneous film much faster than their liquid precursors. Surprisingly, this effect was found to result from the presence of kaolin. Consequently, this additive fulfills a dual purpose in re-dispersible powders, it serves as anti-caking agent and also accelerates film formation while polyvinylalcohol retards particle coalescence. The SB latex achieves a coherent polymer film faster than the EVA dispersion, due to its smaller particle size (~200nm).

The influence of kaolin and calcined kaolin on SBR composite properties

Kaolin is a naturally abundant and cheap ore, which can impart various properties to rubber composites besides lowering its cost. In this work, kaolin and thermally treated kaolin (especially m‐kaolinite), which is the most active species of kaolin were added to styrene–butadiene rubber composites in different concentrations ranging between 10 and 50 phr to study their effect on SBR rheometric, physical, mechanical, and thermal properties. The main aim of this study was to state whether the activity of calcined kaolin will allow it to work as a bifunctional additive (i.e., reinforcing filler and accelerator) or an adverse one (i.e., working as an active radical breaking the polymer chains). The study revealed that SBR containing calcined kaolin performed better properties than those containing kaolin indicating that calcined kaolin worked as a bifunctional additive in SBR composites. POLYM. COMPOS., 35:570–580, 2014. © 2013 Society of Plastics Engineers

Effects of Additives on Barley Straw and Husk Ashes Sintering Characteristics

A growing interest has been observed for producing sustainable heat and power by combustion of residues from local agricultural production. However, ash related problems are inclined to occur due to high contents of problematic ash forming matter in such residues. The aims of this work were to examine ash characteristics of barley straw and husk and to find mixtures of fuels and additives that can be used as basis for producing pellets giving minimal problems during combustion. Influence of kaolin and calcite additives on the two fuel ashes’ sintering behaviors were investigated by X-ray fluorescence (XRF), ash fusion analyzer and X-ray diffraction (XRD) analysis. The results showed that, compared to barley straw ash, the barley husk ash has a higher sintering tendency, with observation of severe melting during combustion. Kaolin and calcite addition increased the melting temperatures of ashes from both barley straw and husk. Reactions between kaolin and potassium containing species in the barley straw and husk ashes were revealed by XRD analyses. With formation of high temperature melting species due to kaolin addition, the severe sintering of barley straw and husk ashes were significantly reduced. The dilution effect from calcite is supposed to be a main reason for improved barley straw and husk ash sintering behaviors. In addition, calcite addition led to formation of more calcium rich phases, which have higher melting points and contribute to low ash sintering degrees. Therefore, by using the additives, agricultural residues can be competitive for energy production in the future.

Influence of kaolin and firing temperature on the mullite formation in porous mullite-corundum materials

The refractory ceramics became very important in both the traditional and the advanced materials applications as it has outstanding thermal and mechanical properties. The refractoriness of ceramics can be achieved by getting the mullite-corundum. Refractory ceramics with high porosity serve as a heat insulator and constructional material. Three series of porous mullite-corundum ceramic samples were prepared from Al2O3 (Nabalox, Germany) and pure SiO2 in 2.57:1 ratio that was conformed to mullite compositions (3Al2O3·2SiO2). α-Al2O3 (d50 = 4 μm) and γ-Al2O3 (d50 = 80 μm) were in 1:3 ratio. Quantity of kaolin (MEKA, Germany) was 10, 20 and 30 wt.%. Porous materials were prepared by slip casting of suspension of raw materials, where the aluminium paste (0.18 wt.%) was used as a pore former. Water content in the suspensions was 38-40 wt.%. Pore formation occured in result of hydrogen formation in chemical reaction between aluminium paste and water. The samples were sintered at 1650, 1700 and 1750°C temperature for one hour. SiO2 and γ-Al2O3 on the contrary reduced mechanical properties, but decreased shrinkage. Using of α-, γ-Al2O3, SiO2 and kaolin in corresponding ratios the samples with open porosity of 30 to 54 vol% were acquired. The relative amounts of pores depended on the initial content of kaolin and on firing temperature.

Influence of Kaolin and Calcite Additives on Ash Transformations in Small-Scale Combustion of Oat

A growing interest has been observed for the use of cereal grains in small- and medium-scale heating. Previous studies have been performed to determine the fuel quality of various cereal grains for ...

Influence of kaolin on methane oxidation by Methylomonas methanica in gas phase bioreactors

Significant levels of methane are liberated from the coal face and subterranean pockets during coal mining. This methane poses an explosion hazard in mines and when released into the atmosphere, acts as a greenhouse gas which contributes to global warming. Methanotrophic bacteria in gas phase bioreactors (GPBs) offer the potential to convert this methane to less deleterious substances; however, it is critical that reaction rates be maximized. The effect of kaolin on rates of methane oxidation by Methylomonas methanica grown in GPBs was assessed. The amendment of GPBs with a 4% kaolin solution significantly increased methane removal by M. methanica versus non-kaolin-amended controls. The maximum velocities ( v max ) were 604.1 mg methane min −1 GPB −1 in the control compared to 1156.6 mg methane min −1 GPB −1 in the kaolin-amended bioreactors, while the Michaelis constants ( K m ) were 15.87 and 60.52 mg methane GPB −1, respectively.

On the asymmetric polymerization of aspartic acid enantiomers by kaolin.

Two recent reports in the literature claim thatl-aspartic acid polymerizes significantly faster thand-aspartic acid in the presence of kaolin in aqueous solution at 90°. The novelty of these observations and their potential significance for molecular evolution and the origin of optical activity in nature has prompted us to attempt a duplication of the experiments involved—using, however, analytical criteria which we felt would be more reliable than those previously employed. In our experimentsl- andd,l-aspartic acid in 0.01M solution were incubated with kaolin at 90° for 8 days. Careful examination of the aqueous residues from such experiments, however, failed to demonstrate any preferential polymerization ofl- overd-aspartic acid under the influence of kaolin, or indeed any significant gross polymerization of aspartic acid at all.

Factors Affecting the Metabolizable Energy Content of Poultry Feeds: 3. The Influence of Kaolin and Alphacel when used as Ration Diluents

WHEN a portion of a poultry feed is replaced with a diluent the utilization of the feed may be changed. Sheehy (1939) observed that high energy chicken diets were less well utilized than ones in which the energy concentration was reduced by the addition of a fibrous feed, while Dymsza et al. (1953) reported that the utilization of the energy of a turkey diet was improved when oat hulls were added to raise the crude fibre content from 5 to 20 percent. Morris et al. (1932) found that a level of 10% crude fibre in the diet did not materially depreciate the coefficients of digestibility of the other nutrients. Halnan (1949) stated that while fibre naturally present in the feed exerts a considerable influence upon nutrient utilization, added fibre has much less influence. It has been claimed that the only effect of fibrous material added to chick diets was to …