Pan Granulator Research Articles

Effect of Flash Calcined Powders on the Properties of Spherical Alumina Granules

Three types of flash calcined powders with different specific surfaces and phases were selected to make alumina granules. The granulation was performed in a pan granulator as the spherical form. The hydrothermal and calcination conditions were applied to the granules. Physical, chemical and microstructural studies were applied to the hydrated and calcined granules. This study focussed on the thermal historical effects of the initial powders derived from bauxite on the granules. The least physical changes and the highest specific surface area were obtained for the granules prepared with flash calcined powder at 650°C. The hydrated granules can have boehmite, gamma and bayerite phases with rod, porous and plate morphologies, respectively. The presence of rod boehmite phase increases the strength of hydrated granules and plays an important role in the final strength. In the calcination stage, the phases transformed into the transition alumina and gamma phases with the growth of nanometer-sized crystals.

ENERGY- AND RESOURCE-SAVING PROCESSES INVOLVING THE POLYMER PHASE

The paper deals with the processes of application and production of various polymer materials. By coating the surface of mineral fertilizer granules with hydrophobic polymer films, fertilizers with controlled release of nutrient components were obtained. Such fertilizers can prevent the leaching of nutrients, prevent the negative impact on the environment and reduce fertilizer consumption. Methods for calculating the particle distribution function by the degree of coating characterizing the uniformity of coating on fluidized bed particles for stationary and non-stationary modes of operation of the apparatus are considered. The process of applying a thick composite coating to the surface of urea granules in a pan granulator was also investigated. A simple method for calculating the size distribution of the obtained granules with a composite shell is proposed. The actual problem of developing a method for predicting the kinetics of nutrient release from polymer-coated fertilizer granules based on a fairly simple mathematical model of the process has been solved. Studies of the combined polymerization and drying process in the synthesis of polyacrylamide and sodium methacrylate copolymer with methacrylic acid amide have shown that its use at the final stage of obtaining water-soluble acrylic polymers is very effective. This technique allows to reduce the total time of the technological cycle. The process of obtaining polyethylene powder by the method of elastic-deformation grinding of polymer gel and a two-stage process of solvent removal from polymer powder with the return of the solvent to the technological cycle has been developed. The rational technological parameters of the electrodialysis process of contaminated steam condensate of mineral fertilizers plant have been identified, which allows to obtain a more concentrated salt solution, which is used as a secondary raw material, as well as a desalinated solution used as process water. For citation: Lipin A.G., Lipin A.A. Energy- and resource-saving processes involving the polymer phase. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 7. P. 203-213. DOI: 10.6060/ivkkt.20236607. 6836j.

Process Behavior and Product Quality in Fertilizer Manufacturing Using Continuous Hopper Transfer Pan Granulation—Experimental Investigations

Fertilizers are commonly used to improve the soil quality in both conventional and organic agriculture. One such fertilizer is dolomite for which soil application in granulated form is advantageous. These granules are commonly produced from ground dolomite powder in continuous pan transfer granulators. During production, the granulator’s operation parameters affect the granules’ properties and thereby also the overall performance of the fertilizer. To ensure product granules of certain specifications and an efficient overall production, process control and intensification approaches based on mathematical models can be applied. However, the latter require high-quality quantitative experimental data describing the effects of process operation parameters on the granule properties. Therefore, in this article, such data is presented for a lab-scale experimental setup. Investigations were carried out into how variations in binder spray rate, binder composition, feed powder flow rate, pan inclination angle, and angular velocity affect particle size distribution, mechanical stability, and humidity. Furthermore, in contrast to existing work samples from both, pan granules and product granules are analyzed. The influence of operation parameter variations on the differences between both, also known as trajectory separation, is described quantitatively. The results obtained indicate an increase in the average particle size with increasing binder flow rate to feed rate and increasing binder concentration and the inclination angle of the pan. Compressive strength varied significantly depending on the operating parameters. Significant differences in properties were observed for the product and the intermediate (pan) samples. In fact, for some operation parameters, e.g., binder feed rate, the magnitude of the separation effect strongly depends on the specific value of the operation parameter. The presented concise data will enable future mathematical modeling of the pan granulation process, e.g., using the framework of population balance equations.

The Durability of Mortar Containing Alkali Activated Fly Ash-Based Lightweight Aggregate.

Beneficiating fly ash as valuable construction material such as artificial lightweight aggregate (LWA) could be an alternative solution to increase the utilization of the industrial by-product. However, generally, LWA is characterized by high porosity and a related high water absorption, which on the one hand allows production of lightweight mortar, but on the other hand can affect its performance. Thus, in this research, the durability performance of mortar composed with alkali-activated fly ash-based LWA, and commercial expanded clay (EC) LWA was investigated. The fly ash LWA was prepared in a pan granulator, with a 6-molar solution of NaOH mixed with Na2SiO3 in a Na2SiO3/NaOH weight ratio of 1.5 being used as activator (FA 6M LWA). The results revealed that mortar containing FA 6M LWA had equivalent mechanical strength with mortar containing EC LWA. The mortar containing FA 6M LWA had comparable capillary water uptake and chloride migration resistance with the reference and EC LWA mortar. Furthermore, the addition of FA 6M LWA was proven to enhance the carbonation resistance in the resulting mortar, due to the denser interfacial transition zone (ITZ) of mortar with LWA.

Particle coating with composite shell in a pan granulator

In this study, the coating of urea granules with a composite shell was performed in a laboratory-scale pan granulator. The composite shell of coated particles consisted of a filler and a binder. Aqueous solutions of sodium silicate, methylcellulose, and polyacrylamide were used as the binders. Powdery calcium carbonate was used as the filler. The influence of the pan rotation speed, the pan-tilt angle, and the binder type on coating performance and the product properties was investigated. The pan rotation speed varied in the range from 30–70 rpm and the pan-tilt was changed from 30° to 75°. The relative shell mass, crushing strength, moisture content of the coated particles, and particle size distribution (PSD) were determined. A mathematical model was developed based on the population balance equation with the main purpose of predicting PSD. Particles’ weight gain was assumed to be proportional to the ratio of the surface area of the given size particles and the surface area of all particles in the coater. A comparison of calculated and experimental cumulative distributions of particle size was performed. Good agreement was observed between the modeling and the measurements.

Study of the pilot-scale pan granulation of zeolite-based molecular sieves

This work describes a systematic study of the granulation process of a 5A zeolite into molecular sieves. Initially, a 5A zeolite was synthesized at the pilot scale and subsequently granulated in a core–shell structure using a rotary tilted pan. The effect of water content of the paste, pan rotating velocity and inclination, proportion of zeolite in the core and shell, shell thickness, the type of binding clay, and the calcination temperature were studied. The effect of these variables on the shape, size, water adsorption capacity, and crush resistance of the agglomerates was assessed. According to the results, suitable bead shape and size were obtained at high rotation velocity (59 rpm), low pan inclination (60°) and with 30 wt. % of added water. High content of zeolite in the core and shell provided suitable adsorption capacity, but lower crush resistance. Actigel 208® exhibited better binding performance and the recommended calcination temperature was 873 K.

A Manufacture of Phosphate Fertilizer from Cow Bones Waste

Cow bone waste was the fundamental problems that occur in several abattoirs (slaughterhouses) in Indonesia that untapped optimally. Intention of this research studied of making phosphate fertilizer from cow bone wasted by granulation process with the effect of concentration phosphoric acid and sulfuric acid to the quality of phosphate fertilizer. The process of making phosphate fertilizer was by preparation of cow bone waste until became into powder and filtered it with 80 mesh of sieve. Pan granulator ran with cow bone powder and sprayed with sulfuric acid-phosphoric acid solution according to specified variable. Then the results of granulation taken from a pan granulator and dried using an oven with a temperature of 70oC for 3 hours. The chemical composition of dried products were analyzed using XRF (X-Ray Fluorescence) analysis. Analysis results showed that phosphate fertilizer can be produced by cow bone waste deliver the highest P2O5 was 30.7% with addition H2SO4 5% and H3PO4 45%.

The effect of NaOH concentration on the mechanical and physical properties of alkali activated fly ash-based artificial lightweight aggregate

Natural aggregate is a non-renewable material that takes up a large portion of a concrete mixture. Replacing this material with artificial lightweight aggregate (LWA) that is generated from an industrial by-product such as fly ash, will reduce the impact on the environment. Alkali-activation proved to provide better properties to the LWA compared to the use of the fly ash in a blend with Portland cement. In this research, the NaOH concentration of the activator was varied (4 M, 6 M or 8 M) in order to obtain the optimum for producing LWA. Sodium silicate was combined with the sodium hydroxide in a weight ratio of 1.5. The LWA were produced by adding the activator to the fly ash in a pan granulator and the particles of 2–4 mm diameter were used to replace the fine natural aggregates in the mortar. The mechanical and physical properties of the produced LWA were investigated, such as water absorption, density, porosity, particle size distribution, crushing resistance, and mineralogy, as well as the compressive strength of the resulting mortar. The results showed that increasing the concentration of NaOH up to 8 M had no significant effect on the density, water absorption, particle size distribution, mineralogy and the crushing strength of resulting LWA. A significant decrease in the amount of macropores occurs when the concentration of NaOH is increased from 4 M to 6 M. The maximum compressive strength of 64 N/mm2 at 28 days could be achieved by mortar containing LWA with 8 M NaOH. The properties of fly ash-based LWA in this research were comparable with LWA generated from commercial expanded clay.

Utilization of Chitosan as Coating Material in Making NPK Slow Release Fertilizer

AbstractIn the implementation of fertilization, only about 50% of the fertilizer can be absorbed by plants while some are degraded or drifted by groundwater so that fertilization becomes inefficient which will also pollute the environment with the content of N, P, and K. The loss of N as nitrogen gas due to denitrification is up to 30–40%, the loss of N as ammonia gas due to volatilization is about 10–20, the loss of N as nitrate due to the washing by water flow is about 44%, and erosion can reach 45%. One solution to this problem is using a slow release fertilizer (SRF) where the nutrient is released slowly within a certain time. The SRF technology modifies the fertilizer utilizing chitosan coating on granule surface of the fertilizer. Liquid chitosan is used for coating and it is sprayed on the surface of fertilizer granule in the rotary pan granulator. It is found that the resistance of the chitosan coated fertilizer in the water is about 3–6 months. The characteristics of the nutrients released from SRF NPK 16‐16‐16 coated with chitosan are about 103.26 mg nutrients of N, 21.8 mg nutrients of P, and 65.62 mg nutrients of K within a month of immersion time.

The effect of adhesive type and speed pan granulator on the properties of urea slow release fertilizer

The application of slow-release fertilizer (SRF) to agriculture provides many benefits. Productivity increases and at the same time, negative impacts decrease. This type of slow-release matrix fertilizer offers an excellent solution for increasing nutrient uptake by plants and restoring agricultural land. The objectives of this research are to study the effect of the type of adhesive and the rotational speed of the granulator on the physical properties of urea slow-release fertilizer (USRF). There are four characteristics used as responses, namely; bulk density, water absorption, granules yield, and durability. The granulation process is carried out using a disc granulator. The study was conducted using one factor at a time method. Research has been carried out by varying the rotation speed of the granulator 5 to 25 with a range of 5 rotations per minute on five adhesives, namely; tapioca flour, glutinous rice flour, rice flour, sago flour, and corn flour. The results showed that the types of adhesives affect the values of bulk density, water absorption, granules yield, and durability. The best type of adhesive is tapioca, however, USRF tapioca adhesive has weakness on water absorbency. Increasing the rotational speed of the granulator causes an increase in the value of bulk density, water absorption, and granules yield while the endurance parameters decrease.

Poly-acrylic acid grafted natural rubber for multi-coated slow release compound fertilizer: Preparation, properties and slow-release characteristics

In this study, a novel multi-coated slow release compound fertilizer based on natural rubber (NR) was prepared and characterized. Firstly, NR was grafted with poly-acrylic acid by in-situ radical solution polymerization to synthesize poly-acrylic acid grafted natural rubber (NR-g-PAA), the reaction conditions were optimized to increase the water absorption properties of NR-g-PAA. Through a series of characterization and test, the structure, morphology, thermal properties and biodegradability of NR-g-PAA were determined. Subsequently, a multi-nutrient fertilizer core was fabricated with urea, KH2PO4, and attapulgite by pan granulation. Then the fertilizer core was coated by NR as the inner layer and NR-g-PAA as the outer layer. Meanwhile, the slow release behavior of the compound fertilizer in soil was also studied. Results showed that the maximum water absorbency of NR-g-PAA is 744.00 ± 14.38%. The release rate of N, P and K in 30 days for NR/NR-g-PAA coated fertilizer was about 54.35 ± 1.49%, 51.18 ± 2.15% and 44.37 ± 1.38%, respectively, showing that the nutrient element release can last for >30 days. Overall, the novel method introduced in this study can inform the development of NR based controlled release fertilizers.

PENGARUH PENAMBAHAN FILLER BLOTONG TERHADAP POTENSI CAKING PUPUK MAJEMUK GRANUL

The physical quality of NPK fertilizer is very important, good physical quality, as indicated by the low potential of caking and absorption-penetration of water so that NPK fertilizer can be stored for a longer time and easier in handling. In this study, the granulation test used NPK 15-15-15 + 5S formula with the percentage filter pressmud 0%, 60%, 70%, 80%. 90% and 100% in two types of K sources: MOP (KCl) and SOP (K2SO4). Granulation was carried out using the wet granulation method using pan granulator, 2 kg batch-1 capacity, rotation speed 23 rpm and 50o pan slope. The purpose of this study was to determine the effect of filter pressmud addition on the tendency of caking NPK 15-15-15 + 5S products during storage. The results showed that the addition of pressmud filler in the production of NPK fertilizer was obtained: the addition of filter pressmud as a filler in the production of 15-15-15 + 5S NPK fertilizers can reduce the potential of caking by 1.77% -44.31% depending on the formulation of raw materials used.

Filter Cake Utilization as Filler of 15-15-15+5S Compound Fertilizer: Particle Size Distribution and Granule Crushing Strength Properties

Compound fertilizer which combining organic-inorganic materials need to be developed to improve the effectivness of fertilizers in the soil. Filter cake as a material has highly potential to be used as a filler in physical process granulation of compound fertilizer. In this study, the particle size distribution and granule crushing strength properties were tested using 15-15-15 + 5S fertilizer compound formula, which are varied in the filler composition and K sources. Potassium sources consisted of 2 (two) types of fertilizers i.e KCl and K2SO4. Filler composition as a binder in fertilizer granulation consists of 5 combination filter cake and clay ratios (60:40, 70:30, 80:20, 90:10 and 100:0). Granulation carried out by the granulation method using pan granulator of 2 kg/batch capacity, 23 rpm rotation speed and 50o pan slope. The results of the research showed that statistically the combination of filter cake and clay 70:30 had a size distribution and hardness of granules not significantly different from standard fertilizer (100% clay). Keywords: crushing strength; filler; filter cake; granulation; size distribution

Zeolite coated urea fertilizer using different binders: Fabrication, material properties and nitrogen release studies

Abstract Zeolite is the most widely used coating material in developing controlled release fertilizers (CRF) due to low cost and its inherent cation exchange property that effectively controls the nutrient release rate. Using an appropriate binder is the key in fabricating structurally stable zeolite based CRF due to the poor binding behavior of zeolite. In this research, five different binders, namely corn starch, potato starch, bentonite clay, white cement, and acrylic polymer were used in fabricating zeolite coated urea CRF using a pan granulator at different operational conditions. The fabricated CRFs (using five different binders) were characterized by particle size distribution (PSD), structural stability, crushing strength, elemental analysis, Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Nitrogen release rate from the CRFs was investigated by laboratory studies. The zeolite coated urea with acrylic polymer binder (UZ-AP) was found to be structurally stable with high crushing strength. The SEM analysis revealed that UZ-AP had dense coating and tiny pores with 135- 150 μ m coating thickness. The FT-IR analysis predicted the hydrophilic nature of the CRF. The UZ-AP controlled the nitrogen release by 54.7% compared to other CRFs. Thirty days soil column study for UZ-AP and urea concluded that leaching of nitrogen decreased by 65% compared to urea fertilizer. This newly developed zeolite coated urea could be a potential nitrogen fertilizer with controlled release property for efficient crop nitrogen management.

Preliminary Study of a Method for Obtaining Brown Coal and Biochar Based Granular Compound Fertilizer

A purpose of the research was to develop a method for the preparation of novel organo-mineral fertilizers with the use of brown coal and biochars as organic additives. Brown coal was blended simultaneously together with inorganic materials used for the process of urea superphosphate production in a laboratory scale using a pan granulator and in larger scale using a rapid mixer granulator. Biochars were used for the coating purposes of the urea superphosphate granules on a laboratory scale using a pan granulator. Moreover, the aim was to measure and evaluate the physico-chemical properties of organic materials and the obtained organo-mineral fertilizer products and to study the effects of these products on the selected yield components of spring wheat such as grain yield per plant, spike number per plant, and plant height, in pot trials. Results showed that brown coal and biochars can be used as raw materials for production of fertilizer products. Brown coal contained about 50% of total humic acids while biochar contained nearly 6% of total humic-like substances. Brown coal based compound fertilizer granules produced in the large scale were characterized by particle hardness from 15.80 to 23.3 N while those produced in the laboratory scale were classified as “soft” (particle hardness below 2.3 N). The application of brown coal based fertilizers and two studied biochar coated fertilizers had a positive impact on the grain yield per plant of spring wheat.

Slow Release NPK Fertilizer Preparation from Natural Resources

Preparation of Natural multi-nutrient Slow Release Fertilizer (NSRF) aims to reduce the environmental burden from some waste and increase the efficiency of fertilizer in releasing nutrient content. In this study,slow-release fertilizer was prepared from all natural components from waste which aredried chicken manure (N source), struvite (P source), and palm empty fruit bunch ash (K source). The equal weight of the three main nutrient sources was used with the addition of starch powder as the binder by 10%, 15% and 20% of the total nutrient mixture. The mixture of all nutrient with binder was granulated using pan granulator. Dried NSRF granule was tested using sand bed release method to observe the release profile of the contained nutrient. Based on the results of a 30-day leaching study, it was found that increasing concentration of binder will reduce the release of the nutrient from NSRF granules.

Synthesis of porous bentonite organoclay granule and its adsorption of tributyltin

We report a new method to synthesise porous organoclay granules which is suitable for high flow rate wastewater treatment applications. Granulation process consists of three steps: mixing natural clay powder, fine coal dust and corn starch into a homogeneous mixture; granulating in a rotating tilted pan granulator by spraying water mist; and heat treatment firstly at 190°C for 30min to solidify and then calcined at 550°C for 4h to create pores. These procedures produced very strong porous clay granules with a crushing strength of 8.41N, the permeability of the granules was 1.56×106mD and hydraulic conductivity of 1.5cm/s. To further enhance the adsorption performance, the granules were later modified by surfactant hexadecyltrimethylammonium bromide (HDTMA) and tested for its adsorption capacity for removing toxic antifouling agent tributyltin (TBT) at high flow rate. It was found that cationic HDTMA modification enhanced the TBT adsorption capacity by 20%. This new granulation method allows the mass production of porous organo clay granules while the porous granular clay is also a good substrate for coating material such as nano sized zero-valent iron to further extent its application.

Granulation of ammonium chloride fertilizer and agglomeration mechanism

The granulation of ammonium chloride (AC) fertilizer has been investigated in a laboratory scale based on the pan granulator at ambient temperature. Significant improvement of granulation efficiency of AC was achieved by using polyaluminium chloride (PAC) as solid binder and urea as granulation additive. Highly charged cations by PAC hydrolysis could reduce the electrostatic force of AC, resulting in efficient particle agglomeration. Analyzing the surface structure and characteristics of the PAC and AC granules revealed their interactions, which lead to the formation of aggregate nucleus. Furthermore, PAC contained a larger number of active groups, which served as bridges to form particle-polymer-particle complex, and facilitated the growth of particle. Meanwhile, urea and AC could react with each other to form stable inclusion complex which also had pronounced effect on the increase of granulation rate for AC.

Hybrid brown coal-urea fertiliser reduces nitrogen loss compared to urea alone

Synthetic nitrogen (N) fertilisers, such as urea, are susceptible to rapid dissipation from soil. More gradual release of mineral N from fertiliser may reduce the off-site movement of mineral N, thereby enhancing N supply to crops and minimising negative off-site impacts. We hypothesised that granulation of urea with humified brown coal (BC) delays mineral N release and maintains higher concentrations of N in soil than conventional urea granules. Four different brown coal-urea granules, with C:N ratios of 1‐10, were prepared by pan granulation. Advanced spectroscopic and X-ray powder diffraction (XRD) techniques confirmed loading of urea-N into the BC structure. Nitrogen-release from BCU granules was slower than from urea, resulting in higher N retention over a longer period for increasing growth and N uptake by crop plants. This trend increased with higher loading of BC, emphasising the significant role of BC in N retention. These findings support the hypothesis that BC is suitable for developing slow release N fertilisers.

Obtaining of granular fertilizers based on ashes from combustion of waste residues and ground bones using phosphorous solubilization by bacteria Bacillus megaterium

The article presents research results on obtaining phosphorus granulated fertilizers on the basis of microbiologically activated sewage sludge ashes, ground bones and dried blood from meat industry. Granulation tests were carried out using a laboratory pan granulator as well as on an experimental pilot plant. The aim of the studies was to select the proper composition of the mixture of raw materials and binding agents to obtain granulated fertilizers from waste materials such as MSSA and MBM and bacteria lyophilisate. Obtained fertilizer samples were subjected to physical tests (granulation tests etc.) and quality assessment. The tests confirmed that it was possible to produce granulated phosphate fertilizers using the Bacillus megaterium for solubilization of phosphorus in a simple process.