Tyler Mesh Research Articles

Incorporation of Rheological Characterization in Grinding and Tailings Slurries to Optimize the CMP Magnetic Separation Plant

Compañía Minera del Pacífico (CMP) is the main iron producer on the Pacific coast of the American continent. The Cerro Negro Norte (CNN) operation of CMP is facing important challenges, such as the processing of low-grade ores containing complex gangue minerals which negatively affect the performance of the magnetic separation, grinding and solid–liquid separation stages. CMP is working on a program, aimed at optimizing the efficiency of the CNN plant, which considers a rheological characterization of the slurries produced by the different ores treated, information which will be useful to optimize the performance of the physical separation processes. The objective of this work was to characterize the slurries obtained from the secondary grinding and tailings thickener stages through rheological measurements. The rheological data were correlated with the physical, chemical and mineralogical characteristics of the different geological units (GU) tested. The results show that the rheological flow curves of the slurries taken from the secondary grinding product display a pseudoplastic behavior which follows a Casson model pattern. An exponential model was used to correlate the Casson yield stresses with the solids content of the slurries taken from the secondary grinding product. The results of this fitting process indicate that the yield stresses increase with the % −325# Tyler mesh and with the percentage of minerals with a tendency to generate fines (MTF = smectite + illite/mica + talc + chlorite + kaolinite), and in contrast the yield stresses decrease with the ore iron grade (Fe). For the tailings characterization, the results of settling rates and turbidity values of the supernatant obtained from tests with different GU samples show no significant differences. A linear regression model was used to correlate the results of yield stresses of compacted tailings with the chemical and mineralogical characteristics of the GU. The results of the fitting process indicate that the MTF content in the head ore samples influence the rheological properties of the tailings, which correlates with the behavior of the secondary grinding product. The increase in the GU iron grades also reduced the Casson yield stress. The experimental results were explained in terms of the microrheological effects and the physicochemical properties of the different types of phyllosilicates existing in the ore samples tested in this work.

Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.

SÍNTESIS DE UN GEOPOLÍMERO Y USO DE LA METODOLOGÍA DE SUPERFICIE DE RESPUESTA PARA OPTIMIZAR SU ADHERENCIA EN LADRILLO ROJO PARA SU USO COMO RECUBRIMIENTO INTERNO EN HORNOS LADRILLEROS

In Mexico, fixed kilns made of red brick are often used today. However, after several burn cycles at temperatures of up to 1000 °C, these kilns may expand, crack and open. In light of that, we worked to obtain a refractory geopolymer that attaches to red brick to use as an internal kiln coating to increase the useful life of the kiln. We studied the consolidation from refractory clays and a solution of commercial sodium silicate ( =1.38, SiO2/Na2O ratio =3.09). This process originates the synthesis of a geopolymer. The clays were previously selected for their refractory characteristics from different clay banks in the municipality of Comonfort, Guanajuato, Mexico; they have been identified as Caolin, Tepozan, and Bauwer. The clays were subjected to a process of grinding and sieving to a particle size of 60 Tyler mesh . Next, they were characterized using energy dispersive X-ray spectroscopy (EDS), which determined that they contained high percentages of SiO2 and Al2O3. The mineralogy of the raw clays was analyzed by powder X-ray diffraction (XRD), yielding high percentages of kaolinite, alunite, quartz and smectite. This composition validates the refractory potential of clays. A simplex-centroid design was used to formulate the geopolymer. The response surface methodology was used for optimization, keeping the commercial sodium silicate concentration constant. The adherence of the formulated geopolymer on red clay brick was taken as a response variable, yielding 50% for the consolidating material (commercial sodium silicate), 21% for Caolin, 23% for Tepozan, and 6% for Bauwer, where the curing time was 7 days and the burning cycle was 8 hours at 1000 °C. This property was measured in a universal testing machine. The best fit was a quadratic model with synergistic interactions between all factors, and the mean adherence of 28.11 kgf/cm2 (2.8 MPa) was obtained. Common potential applications of geopolymer coatings include protection against salt corrosion of marine concrete, reinforced concrete manufacturing, concrete infrastructure rehabilitation, fire inhibition, resistance to temperature and corrosion and as heat insulators. Geopolymers may also have promising use in construction due to their similar strength and durability properties as conventional concrete. The red brick joined to the obtained geopolymer can be used as an internal coating in fixed brick kilns to increase its useful life. In addition, it has potential use for bonding materials that may be exposed to temperatures below 1000 °C or for replacing concrete in ovens exposed to high temperatures.

Influence of Source and Particle Size on Agricultural Limestone Efficiency at Increasing Soil pH

Core Ideas Liming materials' fineness affected the effectiveness and economics of lime use. There is little information about pelleted lime's efficiency at increasing soil pH. This study assessed the effectiveness of calcitic and dolomitic agricultural limestone (aglime) particle sizes. Calcitic aglime was more efficient than dolomitic aglime at similar particle sizes. Pelleted lime was more effective than calcitic and dolomitic aglime. The chemico‐physical characteristics of liming materials determine their capacity to neutralize soil acidity. This study evaluated how calcitic and dolomitic agricultural limestone (aglime), pelleted calcitic lime, and different particle sizes of both aglime sources increased soil pH. Both aglime sources were fractionated to pass different Tyler mesh sizes (4–8, 8–20, 20–60, 60–100, or 100+). The equivalent of 8.97 Mg CaCO3 ha–1 of each material or powdered CaCO3 was mixed with three acidic soils and incubated for 7, 21, 35, 70, 105, 140, 175, and 210 d. All sources increased soil pH. Differences among soils were minor compared with source differences. The efficiency of lime sources at raising pH relative to CaCO3 increased with incubation time and fineness, and was lower for dolomitic than for calcitic aglime. Pelleted lime, calcitic aglime, and dolomitic aglime efficiencies across all incubation periods were 60 to 90, 47 to 65, and 12 to 47% respectively. Calcitic aglime's efficiency across the incubation periods was –1 to 29, 17 to 39, 24 to 61, 47 to 81, and 70 to 97% for material passing mesh sizes 4 to 8, 8 to 20, 20 to 60, 60 to 100, and 100+, respectively; whereas dolomitic aglime's efficiency was 2 to 12, 4 to 21, 12 to 43, 50 to 66, and 60 to 86%, respectively. The study demonstrated the value of distinguishing between particle sizes passing mesh sizes 60 to 100 and finer, and between calcitic and dolomitic aglime in aglime assessments and agricultural recommendations.

Lithium additives in Aluminium production

Lithium addition to the molten bath during production of Aluminium metal has its benefits in terms of the quality of metal produced. The quantity of lithium salt to be added to the bath is determined by utilising proper material, machine and method. The present study describes the method by two proper routes. One of the methods is by X-ray-Diffraction and other by flame photometric method. The metal standards are used in varied proportion from a considerable range from lower level to an optimum level. Samples of different concentrations are taken by the flake methods of sampling from electrolytic pots. The samples have been divided to two parts as per the standard method of coning and quartering. Samples are ground to -150 Tyler mesh and made in to pellets. Samples are analysed by X-ray diffractometer and flame photometer.

Recycled glass as potential aggregate for concrete tiles: a statistical analysis of the physical and engineering properties

This paper investigates the use of washed post-consumer Recycled Glass (RG) as replacement of 7.5% and 15% silica aggregate in concretes used to manufacture roof tiles. Three grading of RG were studied, defined by the retained particles on the following US Tyler mesh sieves: 4–10 (4.76–1.68mm), 10–20 (1.68–0.84 mm) and 20–50 (0.84–0.30 mm). Metakaolin (MK) was used to replace 7.5% and 15% wt/wt Portland Cement (PC). The physical and engineering properties assessed were dry bulk density, compressive strength, modulus of elasticity, Ultrasonic Pulse Velocity (UPV), apparent porosity and oxygen permeability. The effect of particle size of RG, % RG and %MK on the physical and engineering properties was statistically studied using a full factorial design 33. Results showed that 7.5% RG in combination with 7.5% MK provided equivalent performance to reference semi-dry pre–cast concrete and, therefore, may be used as final route of disposal for RG.

Influence of rubber particle size on properties of recycled thermoplastics containing rubber tyre waste

Recycling represents a valid alternative to the disposal of post-consumer plastics in common landfills only when it is possible to obtain new materials with good final properties through practical applications and above all using inexpensive methods. Considering the problem of the great amount of rubber tyre waste produced worldwide, the objectives of this study are to incorporate particles of tyre rubber (TR) waste scrap into a thermoplastic matrix, post-consumer polypropylene (PP) and high impact polystyrene (HIPS) and to evaluate the rheological, physical and mechanical properties. The thermoplastic materials used were ground, washed, dried and ground again into flake form. The particle sizes of the TR used were <500 and 500–1000 μm, separated using a system of sieves of the Tyler mesh series. The PP/TR and HIPS/TR composites, both with weight ratios of 90∶10 and 70∶30, were processed by injection moulding. Results for the rheological behaviour showed that the incorporation of TR particles into the recycled HIPS and PP matrix led to opposite behaviours and that the extent of the effect was dependent on the nature of the polymer and the filler type and particle size. In addition, the presence and concentration of TR led to a reduction in the mechanical properties when compared with the unfilled matrix (post-consumer PP and HIPS), as confirmed by SEM images and the physical properties.

Oxidation of Chalcopyrite (CuFeS&lt;sub&gt;2&lt;/sub&gt;) by &lt;i&gt;Acidithiobacillus Ferrooxidans&lt;/i&gt; and a Mixed Culture of &lt;i&gt;Acidithiobacillus Ferrooxidans&lt;/i&gt; and &lt;i&gt;Acidithiobacillus Thiooxidans&lt;/i&gt; Like Bacterium in Shake Flasks

Chalcopyrite bioleaching process using Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans like bacterium was carried out. Two mineral particle sizes were evaluated, 200 and 325 Tyler mesh. The strains were adapted by gradually decreasing of the main energy sources and increasing in the mineral content. The experiments were performed in absence of ferrous sulphate and elemental sulfur. When the mixed culture was used, pH values were always over 2,1, indicating a probable passivation of Acidithiobacillus thiooxidans in the consortium. For both cultures, the Cu2+ dissolution occurred at relatively low redox potential values, around 400mV–450mV, while at high redox potential values, 550mV, chalcopyrite dissolution was inhibited. Copper lixiviation was around 40% for both tests. The Fourier Transform-Infrared spectra showed that the main oxidation phase is jarosite. The results showed that chalcopyrite oxidation is more dependent on the redox potential than particle size or type of culture used.

A comparison of Bygholm feed sieve to standard particle-size analysis techniques (2005)

Three experiments were conducted to evaluate the Bygholm Feed Sieve particle size tester. The Bygholm Feed Sieve is an 11 inch × 2.25 inch × 4.25 inch plastic box divided into four compartments by three different screen sizes (3,000-, 2,000-, and 1,000-micron mesh). In Experiment 1, particle size was determined for 20 ground corn samples with a Ro-Tap 13-sieve stack (53to 3,350-micron Tyler mesh screens).The particle sizes ranged from 543 to 1,741 microns. Samples were analyzed for particle size with the standard Bygholm Feed Sieve, operated according to the manufacturer’s directions. In Experiment 2, two rubber balls were placed on the 2,000 micron screen and one ball was placed on the 1,000 micron screen in the Bygholm Feed Sieve to aid in moving particles through the screens. Samples were then analyzed for particle size, according to the manufacturer’s directions. In Experiment 3, 24 additional samples with particle sizes ranging from 604 to 1,305 microns were analyzed to determine the accuracy of the regression equation created by Experiment 1. After initial analysis indicated that the equation didn’t accurately predict particle size of samples with a large particle size, an additional 11 samples with particle sizes ranging from 1,054 to 1,741 microns were analyzed. After this analysis, all samples from Experiments 1 and 3 were used to develop a new set of regression equations to calculate the particle size of samples over a wider micron range. The Bygholm Feed Sieve more accurately predicted the particle size of samples when rubber balls were not present within the system (R2 = 0.88 versus 0.82). The regression equation created by Experiment 1 predicted 90% of the samples to be within 100 microns of the actual particle size when the samples were less than 1,000 microns. When samples are coarser than 1,000 microns, however, the regression equation created by Experiment 3 should be used; it predicts 85% of the samples to be within 100 microns of the actual particle size when the samples were larger than 1,000 microns and 98% of all samples to be within 150 microns of the actual particle size.

Adsorption Equilibrium of Water Vapor on F-200 Activated Alumina

Adsorption isotherm data for water vapor on F-200 7 × 14 Tyler mesh activated alumina are obtained at (5, 15, 25, and 35) °C in the range 0% to approximately 95% relative humidity using a static gravimetric technique. F-200 is a commercially available adsorbent that has become very popular in industry for drying compressed air via pressure or temperature swing adsorption. The equilibrium isotherms are presented in tabular as well as in graphical form. The equilibrium data are measured in both directions: adsorption and desorption. A pronounced hysteresis between the adsorption and the desorption legs is present at all temperatures. When plotted versus the relative humidity, the equilibrium data are essentially independent of temperature. The complete removal of the adsorbed water requires regeneration at elevated temperature (290 °C) under vacuum. The data reported in this study can be used in industrial design as well as in the theoretical studies on the adsorption/desorption mechanisms of water vapor o...

Separation and Quantitation of Hazardous Wastes from Abrasive Blast Media

A sample of glass bead abrasive blasting material (ABM) waste, received from Robins Air Force Base (Georgia), was examined to determine whether the waste could be rendered nonhazardous by separating paint contaminants from the ABM. The sample was analyzed with size distribution and toxicity characteristics leaching procedure. A Microtrac analyzer was used to measure the size of fine particles (-325 Tyler mesh), and scanning electron microscopy analysis was performed to identify the nature of the contaminants in the ABM waste. Tests using froth flotation, magnetic separation, desliming, and acid washing were conducted to develop a process for removing the contaminants. A pilot plant test using the developed process rendered 82.1% or the ABM waste material nonhazardous.

A comparison of different particle size analysis techniques (2001)

In this study, we compared different methods of testing particle size of ground corn. Forty-four corn samples were analyzed for particle size with a Ro-Tap tester equipped with a 13-sieve stack (53 to 3,350 :m tyler mesh screens). Mean particle size of the 44 samples ranged from 422 to 1,143 :m. These samples were then analyzed by placing 280 g on a #14 sieve (1,400 :m). The sieve was shaken by hand as the manufacturer recommended (one-sieve method). In a second procedure, samples were analyzed by placing 50 g of corn on a stack of three sieves: US #12 (1700 :m), #30 (600 :m), and #50 (300 :m: three-sieve method) with balls and carnucles. The three-sieve method was much more reliable in predicting average particle size of ground corn than the one-sieve method when compared to the 13stack standard operating procedure. In summary, the three-sieve procedure may be a more accurate method to quickly determine particle size than the one-sieve method.

98/03655 Liquid fuel by thermochemical conversion of municipal refuse in Shellsol AB

This chapter discusses the pretreatment of coals with supercritical solvents under coal liquefaction conditions. In a study described in the chapter, sample coals were dried in an atmosphere of nitrogen, were ground to pass 200 Tyler mesh, and were slurried with a large amount of the concerned solvent. Most of the experiment was carried out at temperatures of 400°C under high pressures of 20, 40, and 60 MPa using a self-made tubular-type reactor. The products were recovered and divided into low-boiling fractions as a distilled solvent and a high-boiling fraction as residue. This was accompanied using a vacuum distillation until the distillates were no longer detectable. The high-boiling fraction was further fractionated into hexane-soluble, benzene-soluble, tetrahydrofuran-soluble materials, and unreacted residue. In tetralin, the coal conversion gradually increased up to 100 daf %; the pretreatment profiles were similar with those of usual coal hydroliquefaction profiles.

Desulfurization of Illinois No. 6 bituminous coal via reductive carboxylation in absolute ethanol

This study detailed the sulfur removal from Illinois No. 6 bituminous coal through reductive carboxylation in absolute ethanol. Maximum desulfurization (68 %) occurred at 300 °C using 10 g of sodium hydroxide, 500 mL of ethanol, and 10 g of 250/325 Tyler mesh coal. Sulfur removal increased with an increase in reaction temperature, lower base concentration (10 g vs 20 g of NaOH), and the use of carbon dioxide. The improved desulfurization of reactions which used carbon dioxide was the result of selective carboxylation of organosulfur compounds. The mass recovery of original coal samples ranged from 77 % to 91 %, with the lower values occurring at higher temperatures. Conversely, heat content values increased as the temperature was increased

Investigation of parameters affecting atmospheric extraction yields and extract qualities of two Turkish lignites

Four sets of extractions of two Turkish lignites have been performed at atmospheric pressure in Soxhlet-type extractors varying the time of extraction, particle size of the lignite, its moisture, and the solvent. Extractions performed in small-size Soxhlet extractors (capacity 90 g coal) with benzene as the solvent have shown that for the Mengen lignite the most appropriate size range is 20–60 Tyler mesh and the moisture content leading to highest yield is 10–12 per cent. For the Elbistan lignite the corresponding values are 10–60 Tyler mesh and 20 per cent moisture. Extractions carried out with benzene in a larger-size Soxhlet apparatus (capacity 1–1.5 kg coal) have shown that Mengen lignite should be extracted for 30 hours and Elbistan lignite for 24 hours for exhaustion. Most of the extractable material can be obtained in the first five hours in the case of Elbistan lignite and in the first 10 hours in the case of Mengen lignite; the difference is attributed to different porosities. Extractions carried out using various solvents in larger-size Soxhlet extractors under the most appropriate conditions as determined from the first three sets of experiments have indicated that Mengen lignite may be a promising raw material for industrial-scale montan wax production. Yields varying between 10 and 14 per cent on dry basis have been obtained from Mengen lignite with benzene—ethanol, benzene—methanol and tetrahydrofuran as solvents. Elbistan lignite gives a maximum yield of 3.5 per cent with tetrahydrofuran. Solvents characterized by a high substitution ability yield more extract. Montan waxes obtained from Mengen and Elbistan lignites are found to be richer in free acids and esters compared with commercially available ones. Infrared spectra results indicate the raw wax to be predominantly aliphatic. The melting points of the waxes obtained with various solvents are generally found to increase as the asphaltic matter content increases and resinous matter content decreases.

A respirator cartridge for use in removing methanol vapors

Activated charcoal is the adsorbent generally used in organic vapor respirator cartridges. These cartridges, when challenged with methanol vapor, offer little protection to the user. The purpose of this research was to investigate various materials as possible sorbents for methanol and to test the most promising for use in respirator cartridges. Initial results indicate that silica gel is the most efficient methanol adsorbent. Therefore, service life of silica gel respirator cartridges was studied as a function of concentration, mesh size, adsorbent quantity, resistance to flow, and relative humidity. The most satisfactory results were obtained with the Tyler mesh size #12 to #42, an adsorbent weight of between 95 and 110 g, and relative humidity of less than 65%.

Smaller Gravel and Coated Screens Enhance 50-Year-Old Field

New completion practices currently are being developed and tested in California. This paper describes a recent technique using smaller gravel, coated screens, and a viscous polymer-carrying fluid to complete a well in these unconsolidated formations. Results are encouraging, as is evidenced by the oil production of wells redrilled and completed with this new technique. Introduction The Huntington Beach field is a major oil accumulation lying on the California coastline approximately 20 miles southeast of Los Angeles. Fig.1 shows the location of the Huntington Beach field in the Los Angeles basin, with the offshore area of the field crosshatched. Currently, three of the zones are producing by waterflood, one by cyclic steam producing by waterflood, one by cyclic steam injection, and three on primary production. A drilling program is planned for the one zone not being program is planned for the one zone not being produced. produced. During the last 50 years, there has been a transition toward more efficient oil recovery techniques in the Huntington Beach field. To achieve this end, many drilling and production problems have been overcome. Major production problems are due to (1) the complex geology, (2) the highly deviated wells, (3) the unconsolidated formation, and (4) the corrosive nature of the injection and formation water. Because we cannot alter the geology or the need to drill the wells directionally, we have concentrated our efforts on extending the life of the field by effective sand and corrosion control.The zones where the most recent of these new completion techniques have been initiated are the Upper and Lower Jones zones, both under waterflood. Fig. 2 depicts a cross section of the offshore field. Previous Completion Techniques Previous Completion Techniques Wells drilled from 1930 to 1960 were completed for primary production. These wells usually were primary production. These wells usually were completed with 6 5/8-in. slotted liners in a 7 5/8-in. hole.Full-scale waterflooding began in the early 1960's, and gravel flow packing was initiated to control sand production from the high gross rates from waterflooding. production from the high gross rates from waterflooding. This technique was typical of California-type completions. An 8 5/8-in. protection casing was run and cemented at the top of the oil-bearing zone. The zone was drilled and underreamed to 15 in, and a 6 5/8-in. slotted liner was installed. The liners typically had slots cut 2 in. long, 0.060 in. wide, on 6-in. centers, and in a staggered 28-row pattern. The wells were gravel packed conventionally with various completion fluids as the carrying medium and using 6-9 or 8-12 Tyler mesh gravel. This work mas done using sand control designs of Schwartz.Using these successful techniques, Aminiol U.S.A. Inc. engineered the third largest waterflood (450,000 BWPD) in the U.S. The large volumes of water have created other problems.Corrosion was so severe that some liners would fail in 1 to 2 years, which allowed entry of gravel and formation material into the wellbore. Many different coatings were applied to these liners to combat corrosion and thereby lengthen the life of these wells. Results seemed encouraging after much experimentation. JPT P. 757

Determination of H2O Proton Contents for Coals by the Pulsed NMR Method

Proton FID signals were measured for 9 kinds of coals (<200 Tyler mesh) using a 20MHz pulsed NMR spectrometer, and it was found that some signals consisted of several components which had different T2 values. The percentage of protons having the longer T2 value (T2l) agrees well with that obtained by the usual drying method, and the T2l fraction vanished when heated at 110°C for 2 hrs. Therefore, the fraction may be attributable to H2O protons. The percentage of H2O protons obtained by the pulsed NMR method appears to be be larger than that obtained by the drying method.

Desulphurization of Athabasca petroleum coke by (a) chemical oxidation and (b) solvent extraction

This study concerns the desulphurization of petroleum coke produced by delayed coking of Athabasca bitumen. The coke contains 7.5 wt % sulphur, 99.6% of the sulphur in coke being organic and the remainder pyritic. The coke was treated both with nitric acid and by solvent extraction. During nitric acid treatment, sulphur removal was found to increase with reaction time and the concentration of nitric acid, and to decrease slightly with increase in particle size. About 30% of organic sulphur was removed from −250 Tyler mesh coke particles by 6 N nitric acid for 4 h at 102 °C. The basic mechanism for this treatment is oxidation and solution of organic sulphur compounds by nitric acid. About 50% ash was also removed from the coke. For solvent extraction, o-chlorophenol was used. Sulphur removal was found to increase with extracting temperature and time, and to decrease with increase in particle size of coke. About 19% of the sulphur was removed from −250 mesh coke particles by o-chlorophenol at 160 °C in 2 h. When treated consecutively with nitric acid and o-chlorophenol, about 40% of sulphur was removed from the −250 mesh coke particles.

Granulation of superphosphate in a rotary drum

AbstractUsing water as a binding agent, some of the factors affecting the preparation of superphosphate granules have been investigated. The amount of water added to the material completely dominates the other physical variables in determining the characteristics of the granules formed. An optimum water content was found for which the proportion of granules within a specified size range (–4 + 14 Tyler mesh) was at a maximum.Granulation with simultaneous drying showed that an increase in the drying rate results in a decrease in the rate of granule growth. The speed at which the granulator is rotated to obtain the correct “tumbling action” is influenced by the internal surface of the drum and the presence and design of internal flights.The mechanical strength of superphosphate granules depends on the quantity of binding agent used in the granulation process and the degree of agitation. The dry strength of the granules formed is considerably greater than the wet strength.