Kankara Kaolin Research Articles

The addition of Nigerian Kankara kaolin improves the ash properties of empty fruit bunches during combustion

The addition of Nigerian Kankara kaolin improves the ash properties of empty fruit bunches during combustion

Mixture optimization of synthesized zeolites 4A and 13X for solar adsorption refrigeration application

Abstract In a way to overcome challenges with global warming, the use of fossil fuels in producing environmentally friendly energy towards reducing the ozone layer depletion and greenhouse gas emissions by participating countries is of interest. The adsorption refrigeration system has the advantages of a long lifespan and its environmental friendliness; however, its major disadvantage is the low coefficient of performance, which is a function of adsorbent–adsorbate, with zeolite–water as the most common adsorbent–adsorbate working pair. Zeolites 4A and 13X are the most used zeolite classes due to their higher selectivity for separating mixtures of CO2/N2 and CO2/CH4/N2 and their high-water adsorption capability, respectively. In this study, for the first time, the synthesis of zeolites 4A and 13X from natural sources (Kankara kaolin) and the mixture optimization for solar adsorption refrigeration application were considered. Raw Kankara kaolin, beneficiated Kankara kaolin, calcined Kankara kaolin and synthesized zeolites 4A and 13X were characterized using X-ray fluorescence, while the synthesized zeolites 4A and 13X were characterized using X-ray diffraction. Using the mixture simplex lattice design of experiment, mixtures of zeolites 4A and 13X were developed and characterized using Brunauer, Emmett and Teller analysis to obtain their pore size, specific surface area and pore volume. The statistical analysis produced the mathematical models of the response that were significant for pore size and specific surface area. The analysis proposed an optimal solution of 75 wt% zeolite 4A and 25 wt% zeolite 13X, which gave a desirability of 0.944.

Influence of Firing Temperature on the Physical, Thermal and Microstructural Properties of Kankara Kaolin Clay: A Preliminary Investigation.

In this study, natural deposits of Kankara kaolin clay were collected and investigated in order to determine physical, microstructural, thermal, and firing properties and assess clay’s suitability as starting material for various ceramic applications. Chemical analysis of the clay was performed using XRF. Mineralogical analysis and thermal analysis of the clay were conducted using XRD and thermogravimetric thermal analysis (TGA)/differential thermal analysis (DTA), respectively. In order to assess its ceramic behavior, the clay was fired at 900–1200 °C. Maturation characteristics of fired ceramics were assessed by measuring bulk density, apparent porosity, and shrinkage. It was found that main oxides in the clay are alumina, silica, and potassium oxide, while other oxides are present in trace quantities. Kaolinite, quartz, and illite are the phases found from the XRD results, while mullite ceramic phase formed at firing temperature above 1100 °C. Maturation tests showed that ceramic properties such as bulk density and shrinkage increase with temperature, while apparent porosity decreases with temperature. The results presented in this study prove that the clay is an appropriate material for producing traditional ceramics.

Study on the effect of Kankara zeolite-Y-based catalyst on the chemical properties of liquid fuel from mixed waste plastics (MWPs) pyrolysis

We report in this study the effect of Kankara zeolite-Y-based catalyst on the chemical properties of liquid fuel from mixed waste plastics pyrolysis using a batch reactor. Fourteen set of 200 g of waste plastics comprising 27 wt%HDPE, 33 wt%LDPE, 13 wt%PP, 18 wt%PS, 9 wt%PET were de-polymerized with catalyst and a set without catalyst. The catalyst used comprises of a mixture of zeolite-Y, metakaolin, aluminum hydroxide and sodium silicate all synthesized from Kankara kaolin from Kankara in Katsina state, Nigeria. Fourteen different catalyst combinations derived from design of experiment using Design expert 11.0 were used to produce fourteen different liquid fuel samples, and the liquid sample with the highest yield was determined. Fourier transform infrared spectroscopy was used to detect various characteristic functional groups present in the samples. Furthermore, the various compounds in the uncatalyzed (thermal pyrolysis) and catalyzed samples with highest yield were determined using GC/MS. The results show that the highest yield of liquid fuel from the fourteen catalyst combination was 46.7 wt% while the thermal pyrolysis gave a yield of 66.9 wt%. The GC/MS result shows carbon in the range of C6–C13 and absence of long straight chain paraffins in the catalyzed fuel samples while the uncatalyzed sample has carbon in the range of C7–C20. Consequently, the thermal pyrolysis sample consists of 59%, 36% and 5% of gasoline, diesel and fuel oil, respectively, while the catalyzed sample consists of 93% gasoline and 7% diesel fraction.

The effect of Kankara zeolite-Y-based catalyst on some physical properties of liquid fuel from mixed waste plastics (MWPs) pyrolysis

The effect of Kankara zeolite-Y-based catalyst on some physical properties of liquid fuel obtained from the pyrolysis of mixed waste plastics has been investigated. Combination of zeolite-Y, metakaolin, aluminum hydroxide and sodium silicate all synthesized from Kankara kaolin from Kankara in Katsina State, Nigeria, was used as catalysts. In this study, fifteen experiments were conducted: fourteen set of 200 g of the mixed waste plastics comprising 27 wt% HDPE, 33 wt% LDPE, 13 wt% PP, 18 wt% PS, 9 wt% PET were de-polymerized with catalyst and a set without catalyst (thermal pyrolysis) in a batch reactor. The maximum temperatures for catalyzed and thermal pyrolysis in this study are 350 °C and 490 °C, respectively. The catalyst components were characterized by XRF analysis, while their textural properties were determined from BET technique by N2 adsorption at − 196 °C. A constant catalyst-to-plastic ratio of 1:10 was used for all the catalyzed reactions. The catalyzed liquid sample with the optimum yield of 46.7 wt% was obtained using 10.49 wt%, 32.42 wt%, 27.09 wt% and 30 wt%, of zeolite-Y, metakaolin, aluminumhydroxide and sodium silicate, respectively, while the thermal pyrolysis gave a liquid yield of 66.9 wt%. Furthermore, the liquid products obtained for both thermal and catalytic cracking at optimum yield were characterized for their suitability as fuel. The properties determined were density, viscosity, fire point, and calorific value. The results suggest that catalytic pyrolysis produced liquid products whose properties are comparable to conventional fuels (gasoline and diesel oil) and more suitable for use as liquid fuel than that produced through thermal pyrolysis.

Metakaolinization Effect on the Thermal and Physiochemical Propperties of Kankara Kaolin

Metakaolinization Effect on the Thermal and Physiochemical Propperties of Kankara Kaolin

Chemical investigation of kankara kaolin for its pharmaceutical applications

Chemical investigation of kankara kaolin for its pharmaceutical applications

Synthesis of Gamma-Alumina from Kankara Kaolin as Potential Zeolite Active Matrix

Commercial fluid catalytic cracking catalysts are manufactured using zeolites dispersed on an amorphous matrix, which is mostly alumina. Alumina is widely used as catalyst support in many heterogeneous catalytic processes owing to its high surface area, superior chemical activity and low cost. In compounded zeolite catalyst it serves as the active matrix which aids the conversion of the bulkiest molecules in the feed owing to its larger pore size than zeolite. Large specific surface area gamma-alumina (γ-Al 2 O 3 ) was synthesized by hydrothermal method using Kankara kaolin as starting material. Thermal treatment of ammonium alum prepared from the filtrate of the dealuminated metakaolin was employed to obtain the alumina. Crystalline aluminum sulfate with 39 wt% Al 2 O 3 was obtained at calcination temperature of 800°C with 3 h soaking. Gamma-alumina was produced at 850°C with 3 h soaking time, having specific surface area of 166 m 2 /g. The weight percent of Al 2 O 3 content in the synthesized and commercial gamma-alumina were 85% and 89% respectively as obtained from the XRF analysis. Good comparison was also observed in the diffractogram of the synthesized and commercial gamma-alumina from the XRD analysis. The Scanning Electron Microscopy (SEM) image showed the platy hexagonal shape of the gamma-alumina. Keywords: Gamma-alumina, zeolite, kaolin

ALUMINA PHASE TRANSFORMATION FROM THERMAL DECOMPOSITION OF AMMONIUM ALUM SYNTHESIZED FROM KANKARA KAOLIN

Thermal stability of transitional alumina phases produced from ammonium alum using Kankara kaolin as starting material was studied. Wet beneficiation method was employed to purify the starting material, after which it was calcined and dealuminated with sulphuric acid. The elemental composition, mineralogical, and physiological analyses were carried out using X-ray fluorescence (XRF), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques respectively. The ammonium alum was thermally treated by varying the calcination temperature from 700 to 1200°C and varying the time of calcination from 1 to 4 h. The formation of gamma alumina began at calcination temperature of 825°C for calcination time of 3 h, which was found to be lower than reported works of 900°C. It was found to be stable at higher temperature of 1125°C, above which phase transformation to alpha alumina was observed. The observed wide range of thermal stability of the gamma alumina phase gives it good advantage to be used for high temperature applications, such as support for catalyst promoters. Alpha alumina phase formation began at 1150°C and was fully formed at 1200°C. BET specific surface area of 166 m 2 /g was obtained for the gamma alumina phase which was high enough for it application as support for catalyst, catalyst and adsorbent. http://dx.doi.org/10.4314/njt.v36i3.23

DEVELOPMEMT OF PILOT SCALE DEALUMINATION UNIT OF 2.5 kg METAKAOLIN PER BATCH CAPACITY

A pilot-size dealumination unit to handle 2.5kg of metakaolin per batch was designed and fabricated and test run. The metakaolin was prepared from Kankara kaolin. The metakaolin was completely split into silica and alumina. The silica component which was inert to the sulphuric acid used during the reaction and was obtained as a solid product. While the alumina which reacted with the sulphuric acid was obtained in liquid form as aluminum sulphate, known as alum. The dealumination unit comprises of the dealumination reactor, known as dealuminator, acid holding tank and metakaolin slurry mixing tank. The material of construction selected for the dealumination reactor was stainless steel type 304 lined internally with glass to withstand the corrosive environment of the concentrated sulphuric acid at the reaction temperature > 140°C. The capacity of the componentsare; acid holding tank 5 liters;metakaolin slurry mixing tank 20 liters, with 70 W capacity motor and the dealuminator 50 liters, which had pressure relief valve, pressure gauge (0-10 bars) and temperature gauge (0 - 300°C) on the cover. Woven glass fiber cloth was used as lagging material to minimize heat lossto the surrounding. The purity level of the silica obtained from the reaction was above 95%.The endothermic nature of the dealumination process was void of external heating. http://dx.doi.org/10.4314/njt.v36i3.24

ALUMINA PHASE TRANSFORMATION FROM THERMAL DECOMPOSITION OF AMMONIUM ALUM SYNTHESIZED FROM KANKARA KAOLIN

Thermal stability of transitional alumina phases produced from ammonium alum using Kankara kaolin as starting material was studied. Wet beneficiation method was employed to purify the starting material, after which it was calcined and dealuminated with sulphuric acid. The elemental composition, mineralogical, and physiological analyses were carried out using X-ray fluorescence (XRF), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques respectively. The ammonium alum was thermally treated by varying the calcination temperature from 700 to 1200°C and varying the time of calcination from 1 to 4 h. The formation of gamma alumina began at calcination temperature of 825°C for calcination time of 3 h, which was found to be lower than reported works of 900°C. It was found to be stable at higher temperature of 1125°C, above which phase transformation to alpha alumina was observed. The observed wide range of thermal stability of the gamma alumina phase gives it good advantage to be used for high temperature applications, such as support for catalyst promoters. Alpha alumina phase formation began at 1150°C and was fully formed at 1200°C. BET specific surface area of 166 m2/g was obtained for the gamma alumina phase which was high enough for it application as support for catalyst, catalyst and adsorbent. http://dx.doi.org/10.4314/njt.v36i3.23

Chemical Assessment of Kankara Kaolin for its Potential Industrial Applications

Kaolin samples from Kankara in Kastina, North-West Nigeria was analysed to investigate its potential use for different industrial applications. The samples were analysed using Instrumental Neutron Activation Analysis (INAA) with Near Infra-Red analytical techniques. The result showed that Kankara kaolin with Fe2O3 content of 2.4 x 10-5%, K2O content of 0.061%, Na2O content of 0.6% and TiO2 (BDL) meets the specification for paper, ceramic, rubber, porcelain, pharmaceutics and cosmetics and glaze production. Its Al2O3 content of 35.28% also satisfies the requirement for the aforementioned applications except for pharmaceutics and cosmetics for which the value is above the specification (23.5%). The pH value of the kaolin was found to be 5.2, making it useful for most industrialpurposes since pH range for most industrial applications lies in the range of 5-7. The Kankara kaolin was found to be good for most industrial applications.

Synthesis of hexagonal zeolite Y from Kankara kaolin using a split technique

Synthesis of hexagonal zeolite Y from Kankara kaolin using a split technique is presented. The technique entails splitting kaolin to alumina and silica components. These components were further recombined to synthesize zeolite Y. The as-synthesized NaY zeolite was transformed to REY zeolite. Characterizations of the as-synthesized zeolite Y were carried out using X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET) texture analysis, scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy. Catalytic desulfurization of the as-synthesized REY zeolite was studied using microwave assisted desulfurization of model diesel. The Si/Al molar ratio of the as-synthesized NaY zeolite was 4.27. The crystallinity of the as-synthesized NaY and REY zeolites were 79.1 and 56.5% respectively. The as-synthesized NaY and REY zeolites possessed hexagonal morphology with average crystal sizes of 200 and 100 nm respectively. The specific surface area, pore volume and pore diameter of the as-synthesized NaY zeolite were 732 m2 g−1, 0.2611 cm3 g−1 and 1.426 nm respectively. The specific surface area, pore volume and pore diameter of the as-synthesized REY zeolite were 456 m2 g−1, 0.1591 cm3 g−1 and 1.395 nm respectively. Zeolite Y synthesized using the split technique possessed physiochemical properties comparable to the commercial zeolite Y, it was also free of quartz and competing phase impurities reported in previous works. The as-synthesized REY zeolite resulted to 79% sulfur reduction when used as a catalyst in a microwave desulfurization of model diesel at 100 °C for 15 min.

Development and Characterization of Ceramic Matrix Composite (CMC) from Nigerian Kankara Kaolin and Gray Cast Iron Filling

This study developed a ceramic composite material (CMC) for use as a refractory material from “Kankara” clay (kaolin) as a matrix material mixed with gray cast iron (GCI) as reinforcement. The CMCs were prepared by varying the percentage by weight of the gray cast iron using 5, 10, 15, 20, 25, 30, 35, 40 and 45 wt%. Tests were conducted on the developed CMC, using standard test techniques, to determine physical and the mechanical properties of the produced composites. The results for mechanical properties showed improvement in the hardness value from 47% at 5% GCI content to 94% at 45% GCI content; the compressive strength improved from 3.11% at 5% GCI to a peak of 7.15% at 25% GCI and then descended down to 3.74% at 45% GCI content while the ultimate tensile strength improved from 0.75% at 5% GCI to a peak of 1.87% at 25% GCI down to 1.34% at 45% GCI content. Equally, there is an increase in bulk density from 1.74% for 5% GCI content to 2.09% for 45% GCI contentment. The linear shrinkage reduced from 11.57% to 1.15%; water absorption also reduced from 33.68% to 15.20%; apparent porosity too reduced from 42.2% to 16.02%. However, cold crushing strength initially increased with increase in GCI content from 3.89 to a peak of 13.32 V for 25% GCI content and progressively dropped to a value of 5.25 V at 45% GCI content. All the values obtained from the blends are within the recommended values for kiln shelves. However, the CMC developed on 25% GCI content showed the best combination of both mechanical and physical properties required of a good material for the production of kiln shelves.

THE STUDY OF THERMAL EFFECT ON THE SURFACE PROPERTIES OF GAMMA-ALUMINA SYNTHESIED FROM KANKARA KAOLIN.

Gamma alumina is a good material for catalyst support and its surface properties is of great importance. In this study the gamma-alumina (γ-Al 2 O 3 ) synthesized to be used as catalyst support for zeolite catalyst was obtained by calcination of ammonium alum an intermediate product prepared from kaolin which was sourced from Kankara, Katsina, Nigeria. The surface properties were determined using BET technique. BET specific surface area of gamma alumina produced at 825°C for soaking time of 3h was 120m 2 /g while at 850°C for soaking time of 4h the surface area was 140m 2 /g. The pore size and pore volume range from 15nm to 25nm and 0.5cm 3 /g to 0.8cm 3 /g respectively. The XRD pattern obtained at 825°C and 875°C calcination temperatures conformed to the standard pattern of gamma-alumina, having the strong peaks at Bragg angles of 67, 46, 39 and 38°. The SEM image showed clearly the plate-like structure of gamma alumina. Thus kankara kaolin is a promising material for the production of gamma alumina. http://dx.doi.org/10.4314/njt.v35i1.11

Chemical and Physical Comparative Study of the Effect of Wet and Dry Beneficiation of Kankara Kaolin

Chemical and physical comparative effect of wet and dry beneficiation processes for purification of kaolin was studied. X-ray flourescence XRF and particle size analysis of kaolin clay before and after beneficiation were carried out. The Si/Al ratio of the raw kaolin which was 1.90 decreased by 1.6 and 17.9% after the wet and dry beneficiation processes respectively. The clay content of the raw clay which was 48 wt% was improved to 73 wt% after the dry beneficiation while the impurity content was reduced from 52 to 27wt%. http://dx.doi.org/10.4314/njt.v34i2.13

Synthesis of gamma alumina from Kankara kaolin using a novel technique

Synthesis of gamma alumina from Kankara kaolin using simple novel dealumination, precipitation and calcination steps and the product characterization have been presented. The raw clay was wet beneficiated, metakaolinized and dealuminated. Amorphous aluminum hydroxide was precipitated from the aluminum sulfate produced, using sodium hydroxide solution as the precipitating agent. Chemical, mineralogical, physiochemical, morphological and thermal analyses of the products were carried out using XRF, XRD, BET, FTIR, SEM, TEM and TGA/DTA. The aluminum hydroxide produced was subjected to thermal treatment at variable calcination temperatures in the range of 300 to 900°C, gradual phase transformation was observed, a fully formed gamma alumina phase was observed at 900°C. XRF analysis of the various materials at each stage of processing showed a progressive trend of increase in Al2O3 content, at calcination of 900°C the Al2O3 content was 91.02wt.%. The XRD pattern of the alumina obtained at 900°C was similar to that of commercial gamma alumina. The BET surface area, pore volume and pore diameter of the as-synthesized gamma alumina were 102.6m2/g, 0.0305cm3/g and 11.89Å respectively and the crystal size was 10nm. This novel process is an industrially feasible alternative to the conventional Bayer process, and it offers a solution to the environmental hazards posed by the wastes generated by the Bayer process.

Application of Synthesised Zeolite A from Kankara Kaolin for Solar Adsorption Refrigeration

This paper presents the synthesis, characterization and application of a synthesised Zeolite A from Nigerian clay (kankara) for application in solar adsorption refrigeration.On the basis of X-ray diffraction, TGA and DTA experiments Zeolite A was confirmed with and adsorption capacity of 0.3 kg adsorbate / 0.85kg adsorbent, regenerative temperature of below 2000C and structural stability below 8000C. The refrigeration system used in the test consists of a 0.6 by 0.45 m2 parabolic trough concentrator, 0.6m long and 0.25m diameter black coated absorber, an air cooled condenser and cooling box of volume(evaporator) 0.048m3. The refrigerator was constructed and tested at the Mechanical Engineering Department Zaria, Nigeria at location 11.11’NE in the month of April, a month with one of the highest of average solar irradiation of 900W/m2. The lowest evaporator temperature attained was 9.80C with a C.O.P of 28.5%.