Showing papers on "Jet mill published in 2017"

Stability of Pharmaceutical Cocrystal During Milling: A Case Study of 1:1 Caffeine–Glutaric Acid

Abstract: Despite the rising interest in pharmaceutical cocrystals in the past decade, there is a lack of research on the solid processing of cocrystals downstream to crystallization. Mechanical stress induced by unit operations such as milling could affect the integrity of the material. The purpose of this study is to investigate the effect of milling on pharmaceutical cocrystals and to compare the performance of ball mill and jet mill, using caffeine–glutaric acid (1:1) cocrystal as the model compound. Our results show that ball milling induced polymorphic transformation from the stable Form II to the metastable Form I, whereas Form II remained intact after jet milling. Jet milling was found to be effective in reducing particle size, but ball milling was unable to reduce the particle size beyond a certain limit even with increasing milling intensity. The heating effect during ball milling was proposed as a possible explanation for the difference in the performance of the two types of mill. The local increase in t...

Injection molding of tungsten powder treated by jet mill with high powder loading: A solution for fabrication of dense tungsten component at relative low temperature

Abstract: The greater demands on final product quality of powder metallurgy processing have led to an increased demand for metal powders with high quality. In this paper we report the successful preparation of tungsten powder with a near-spherical shape and surface morphology by jet milling process, with the disappearance of agglomeration and the improvement of dispersion, narrow particle size distribution of tungsten powder was achieved. The values of D10, D50 and D90 changed from 2.02 μm, 3.67 μm and 6.34 μm to the original tungsten powder to 1.36 μm, 2.13 μm and 3.19 μm for the treated tungsten powder, respectively. The process increases apparent density and tap density from 3.71 g/cm3, 5.54 g/cm3 to 5.71 g/cm3, 8.47 g/cm3. Due to the optimization of the powder characteristics, the powder loading of the feedstock was raised to 65 vol% for the treated powder. The sintered samples of 65 vol% powder loading is easy to get sinter densification with no cracks and has superior hardness and microstructure at a relative low temperature of 1900 °C.

Production of CuSn10 bronze powder from machining chips using jet milling

Abstract: In this study, an experimental target plate jet mill was designed and used to produce CuSn10 bronze powder from its machining chips. Taguchi method with an L9 orthogonal array was used as experimental design to determine the optimum conditions for the pulverization of the machining chips via jet milling. The effect of process variables including nozzle to target distance, impact angle, and air pressure were investigated. The optimum conditions were found to be 8 cm for nozzle to target distance, a 90° angle between nozzle and target, and an air pressure of 7 bar. Repeated impact cycles lead to the production of finer and more rounded particles, although the rate of size reduction was reduced. The jet-milled powder did not contain any contamination, and the amount of the surface oxide of the jet-milled powder was even lower than that of the initial machining chips. Investigation of the fragmentation of particles revealed that the initial machining cracks were the main sites for breakage during pulverization. In addition, the delta phase in the microstructure of the bronze alloy plays an important role in the propagation of pre-existing cracks as well as creating new cracks.

Fluid-particle energy transfer in spiral jet milling

Abstract: Spiral jet milling is a size reduction process driven by the fluid energy of high velocity gas jets. Inter-particle and particle-wall interactions are responsible for size reduction. The process is energy intensive, but inefficient. The underlying mechanisms for size reduction in the mill are also not very well understood. The optimum grinding conditions are still currently found by trial and error experimentation. In this work, the Discrete Element Method coupled with Computational Fluid Dynamics is used to investigate the effects of different parameters on the particle collisional behaviour in a spiral jet mill. These include the particle concentration in the grinding chamber, the particle size, and the fluid power input. We report on our work analysing the efficiency of energy transfer and how it can be improved by changing the milling conditions and particle properties.

Fluidized Bed Opposed Jet Mill System for Processing Inorganic Materials

Abstract: A jet mill system was built aiming to give values for processing inorganic materials, to be used for different industry. The milling housing of the system is composed of; milling chamber, compressed air nozzles which deliver compressed air in the milling chamber to accelerate sample particles. The classifier wheel is composed of two concentric pieces welded together under argon and coupled to a AC Motor, 0 - 9000 rpm, 2 kW, with AC frequencies convertor. The performances of this jet mill system were tried on five cheap locally available materials, viz. white sand, glass, iron oxide, black carbon and alum. It is possible to get particle sizes of less than 1 μm with narrow distribution of particle sizes.

Jet milling device for stripping graphene and production process thereof

Abstract: The invention discloses a jet milling device for stripping graphene The jet milling device for stripping the graphene comprises a raw material feeding pipe, a quartz stone feeding pipe, a mixed feeding pipe, a jet mill, a cyclone separator, a recycling chamber, a pulse filter, an exhaust fan and a separating tank A material outlet of the raw material feeding pipe and a material outlet of the quartz stone feeding pipe are connected with a feeding hopper of the mixed feeding pipe A material outlet of the mixed feeding pipe is connected with a material inlet of the jet mill The cyclone separator is connected with a material outlet of the jet mill through a pipeline The recycling chamber is connected to the lower portion of the cyclone separator The pulse filter is connected with the upper end of the cyclone separator through a pipeline The exhaust fan is connected with an exhaust port of the pulse filter The separating tank is connected with a material outlet of the pulse filter The jet milling device for stripping the graphene has the advantages of being good in production effect, good in product quality, convenient to use and the like

High-temperature cyclic nitrogen protection crushing and grading production line

Abstract: The invention provides a high-temperature cyclic nitrogen protection crushing and grading production line, which ensures that an obtained product is narrow in particle size distribution, smooth in particle surface, regular in shape, high in activity, excellent in dispersibility, free from such pollution as metals and oxides, and high in purity and meets the requirements of a lithium ion battery material. The high-temperature cyclic nitrogen protection crushing and grading production line comprises a bin loaded with to-be-crushed particles, wherein the outlet of the bin is connected with a crushing area of a fluidized bed jet mill; the crushing area of the fluidized bed jet mill is connected with a grading area; the grading area returns coarse particles not satisfying the requirement on the particle size back to the crushing area to be continually crushed, and fine particles satisfying the requirement on the particle size enter the inlet of a dust collector together with airflow; a material outlet of the dust collector is connected with end product packaging equipment; a non-material outlet at the upper part of the dust collector is connected with the inlet of a first filter; the outlet of the first filter is connected with the inlet of a dryer; and the outlet of the dryer is connected with an admission opening of a compressor.

Method for producing slurry and method for producing composite resin material

Abstract: PROBLEM TO BE SOLVED: To provide a slurry which substantially does not contain a surfactant and has excellent dispersibility of fibrous carbon nano structures.SOLUTION: Provided is a method for producing a slurry containing a fluorine resin, fibrous carbon nano structures, and a dispersion medium, comprising: a mixing step of obtaining a mixture by mixing a fluorine resin particles having a volume average particle diameter of 5 μm to 250 μm, fibrous carbon nano structures, and a dispersion medium; and a dispersion step of dispersing the mixture by means of a wet jet mill, where a surfactant is substantially not used.SELECTED DRAWING: Figure 1

Method for preparing graphene by jet mill and graphene

Abstract: The invention provides a method for preparing graphene by a jet mill and the graphene The method includes mixing flaky metal powder serving as a stripping medium into a graphite raw material, enabling the graphene and the flaky metal powder to impact under the action of the jet mill to achieve cutting and stripping until graphene flakes high in hardness are obtained, collecting the graphene flakes through a cyclone separator on the jet mill, and conducting simple flotation so as to obtain high-purity graphene flakes The prepared graphene is complete in structure, thin and even in distribution The method has the advantages of simplicity in process, rapidity in operation, low cost, reusability in partial materials and high preparation efficiency and is beneficial to large-scale industrialized preparation

Method for processing nanoscale talcum powder through high-temperature and high-pressure steam jet mill

Abstract: The invention discloses a method for processing nanoscale talcum powder through a high-temperature and high-pressure steam jet mill. The method includes the following steps that a, talcum powder raw mineral materials are coarsely crushed and smashed; b, materials obtained in the step a are pre-heated and dried to be delivered into the steam jet mill for ultramicro smashing and surface modification; and c, materials obtained in the step b are delivered into a grader to be graded, materials with the grain size meeting the requirement are collected, and materials with the grain size incapable of meeting the requirement are delivered back to the steam jet mill for ultramicro smashing, wherein a smashing cavity of the steam jet mill is 105-400 DEG C in temperature and 6-15 MPa in pressure, and the pre-heating temperature in the step b is 40-280 DEG C. By means of the method, the energy consumption is low, the smashing force is high, the energy-saving technical requirement is met, the remarkable effect on reducing of greenhouse gas emission is achieved, the method is safe and environmentally friendly, and the social, economic and environment-friendly benefits are good.

Characterisation of jet-milled and spray dried isoniazid for pulmonary administration

Abstract: The aim of this study was to develop a dry powder isoniazid formulation with no or a limited amount of excipients for pulmonary administration. Milled isoniazid showed an excellent particle size distribution for inhalation, however dispersion was poor. In 78% of the dispersion measurements the inhaler blocked, retaining most of its dose. Pure spray dried isoniazid yielded particles too large for pulmonary delivery, but the addition of 5% of L-leucine resulted in spray dried particles of inhalable size. DSC data showed complete crystallinity for all samples, while TGA analysis showed that isoniazid sublimates around 100°C. SEM imaging showed that pure jet milled and spray dried isoniazid particles fused together. Isoniazid spray dried with L-leucine resulted in spherical particles with no fusion visible. The most likely explanation for particle fusion is that isoniazid crystalizes, resulting in solid bridge formation. L-leucine however, forms a coating around isoniazid particles, thereby preventing this phenomenon. Further experiments are needed to show why isoniazid fuses together in the jet mill. A possible explanation is that some isoniazid sublimates due to heat generation during particle collisions, and causes solid bridge formation between particles when it ripens. Further experiments have to show whether isoniazid co-spray dried with L-leucine disperses efficiently and is stable over time.

Two type supersonic speed flat jet mill that spout

Abstract: The utility model discloses a two type supersonic speed flat jet mill that spout, aim at solve present flat jet mill to assault kinetic energy little, and crushing strength is lower, smash hardness in mo shi great problem of loss the during material more than 7 grades The device includes one -level venturi, feed inlet, one -level pay -off nozzle, second grade venturi, pay -off connecting pipe, second grade pay -off nozzle, upper cover plate, lower apron, upper cover inside lining etc The utility model discloses can effective solve above -mentioned most technical problem, it is big that it has the kinetic energy of impact, and crushing strength is high, advantage that energy utilization is high And simultaneously, the utility model discloses a self grading structure, product particle size distribution passes through adjustment parameters and can control in very narrow scope, and simple structure and compactness Preferably, the utility model discloses a super wear shocks resistance the material and makes the inside lining, has improved shock resistance to but utilize inserted buffer structure, it is simpler to make the inside lining change

Device and method for preparing graphene through jet milling

Abstract: The invention discloses a device for preparing graphene through jet milling. The device comprises a mixture feed hopper, a steel powder feed hopper, a jet mill, a cyclone separator, a recovery chamber, a pulse filter and an exhaust fan. The mixture feed hopper and the steel powder feed hopper are connected to the jet mill. The cyclone separator is connected with a discharge port of the jet mill through a pipeline. The recovery chamber is connected to the lower portion of the cyclone separator. The pulse filter is connected with the upper end of the cyclone separator through a pipeline. The exhaust fan is connected with an exhaust port of the pulse filter. Graphene raw materials are subjected to pretreatment. Breakable sodium chloride and magnesium chloride are led in through intercalators. Smashing of graphene is facilitated. The smashing effect is improved. The device has the advantages of being simple in structure, easy to operate, good in smashing effect and the like.

Powder grinding system and method

Abstract: The invention discloses a powder grinding system and method The powder grinding system comprises a control device, a feed bin, a powder delivery device, a feeding steam delivery device, a grinding steam delivery device, an organic coating agent delivery device and a jet mill According to the system, the blanking amount, the mass ratio of feeding steam and the powder blanking amount, the mass ratio of an organic coating agent and the powder blanking amount and the mass difference of the feeding steam and grinding steam are input through an input module, and a control module is utilized to automatically regulate the charging flow of the feeding steam, the grinding steam and the organic coating agent on the basis of the powder blanking amount, so that automatic feeding of the jet mill is realized, the feed rate of the jet mill is stable, and the pressure difference of the feed bin is small Therefore, the jet mill of the system is high in feeding stability and long in service life, and moreover, a prepared fine powder material is high in yield and quality and low in production cost

Method for preparing aluminum nitride

Abstract: A method for producing aluminum nitride is to disclose, which includes injecting a nitrogen-containing gas and a pure aluminum material into a high-temperature jet mill. In the high-temperature jet mill, the injected pure aluminum material reacts with the nitrogen and forms aluminum nitride on the surface. The aluminum nitride is continuously to pulverize in the high-temperature jet mill to form fine aluminum nitride powder. According to the present disclosure, unnecessary cost and complicated processes in elevated-temperature agglomeration is to avoid.

Energy-efficient solvent-free process for the preparation of amino acid metal chelates

Abstract: In the process for producing aminocarboxylic acid and / or hydroxycarboxylic acid metal chelates, a dry mixture of at least one inorganic metal oxide and the solid organic acid is subjected to intense mechanical impact by impact and friction in a mill. This is done according to the invention by introducing the reactants metal oxide and acid particulate into a fluid jet of a jet mill (10) operating without grinding media, wherein mechanical activation of at least one of the reactants by particle collision processes is effected within a reaction space (1) formed in a jet area of the fluid jet and a solid state reaction to the metal chelate is triggered. The new process works very energy efficient with high specific yield.

The estimation of mixture composition on acoustic signals of individual material fraction grinding

Abstract: The determining problem of several fracton mixture srtucture of materials grinding in the gas jet mill is considered. The problem is solved by comparing the standard deviation of the standart power spectral density of acoustics signals of individual fractions and of the mixture ones.