It's a long way from raw materials through the mixture to the finished stone. Many plant components are involved in this process. Only if the system components are matched, can one be assured of a smooth process and economical operation of the block making plant. Learn about our Concrete block production plants.
It's a long way from raw materials over mixture to the finished (Kerb)stone. Masa Kerbstone presses were developed to fulfill among other criteria, the special requirements of the "British Standard" kerbstones. This "British Standard" is still a condition in countries of the Middle East and the UK. Learn about our Kerbstone production plants.
The manufacturing of autoclaved aerated concrete products demands high standards for mixing and dosing of the aggregates, the control of the fermentation process and the control of each production step. Masa's aerated concrete installations are proven advanced technology processes, designed according to customers specific requirements. This approach allows complete solutions to ensure highly efficient, optimised processes resulting in consistent final product quality. Learn more about our plants for the production of AAC.
It's a long way from raw materials through the mixture to the finished sand lime bricks. Many plant components are involved in this process. Only if the system components are matched, can one be assured of a smooth process and economical operation of the sand lime brick production plant. Learn about our Sand lime brick production plants.
The slab press UNI 2000 is the heart of any plant for the manufacture of concrete slabs. In addition, dosing and mixing plants, take-off devices with direct washing units and storage systems as well as machines and equipment for slab refinement and packaging are required. Masa can offer the complete know-how for the production of concrete slabs. This is the decisive advantage for our customers: Planning, design, manufacture, assembly, commissioning, training, maintenance and continuous support during production all from one supplier. Learn about our Concrete slab production plants.
Masa plants and machines are installed and commissioned by our own experienced fitters. Masa relies on qualified personnel, trained in Germany. Read more about the assembly and commissioning of your production line.
The Masa Lifetime service extends far beyond the actual assembly and commissioning of a plant. Masa can rely on specific know-how and an industry experience of more than 110 years. Find out more about the wide range of Masa Lifetime services.
Do you need support with your machine? Masa Support scores in both quality and significantly improved accessibility. Whether "first aid" for technical problems, updates, functional expansions of your production plant or technical questions, the know-how provided by Masa Support covers a wide range of services. Get information now.
One of the keys to increasing productivity and quality is continuous training of the machine and maintenance personnel.The acquired know-how will pay off quickly: You and your employees only know how good a Masa machine or plant actually is, if all functions, tricks and fine adjustments are known. Learn more about Masa Customer training.
It's a long way from raw materials through the mixture to the finished sand lime bricks. Many plant components are involved in this process. Only if the system components are matched, can one be assured of a smooth process and economical operation of the sand lime brick production plant.
Do you want to learn more about the Masa sand lime brick manufacturing process? Inform yourself using the interactive step by step system, as to how a sand lime brick is produced from various raw materials.
Sand lime bricks consist of the two raw materials sand and lime only. For the manufacturing process, water is required in addition. The raw materials that are mostly supplied from local extraction places are stored separately in raw material silos. On the way to the silos, the sand passes a screening station to separate oversize material.
Masa sand lime brick making plants are designed to use at least two different types of sand. The advantage for the customers is that the product quality can directly be influenced by a specific mixture of the different types of sand.
The raw materials sand, lime, and water are exactly dosed and weighed in individual scales and fed into the intensive mixer. In the mixing process, a homogeneous and highly disperse sand lime compound is generated.
By means of transport devices (e.g. belt conveyors and bucket conveyors), the sand lime compound is fed into the reactor . The number of reactors depends on the number of presses. Typically, one reactor per press is used. Advantage: With the help of the Masa mixing plant control system, each press is always supplied with an optimum sand lime compound, also in case of different products.
Inside the reactor, the lime is turned to calcium hydroxide by means of a chemical reaction that is triggered when water is added. This process is completed after approx. two hours, and processing of the sand lime compound can be continued in the press.
Between the reactor and the press, there is a double shaft mixer. To provide the double shaft mixer and the press with constant quantities of sand lime compound, the reactor outlet is equipped with a special discharge system developed by Masa. With the help of the Masa press control system, the quantity of the sand lime compound is adapted to the manufacturing process.
In fully automatic hydraulic presses, the sand lime compound is pressed to bricks. The Masa press control system provides for a uniform compaction of the sand lime compound until the required final height and density of the products is reached.
Different moulding tools enable the manufacture of different brick sizes. Depending on the type of tool, it is possible to manufacture perforated or solid bricks with or without tongue and groove or holes for handling or chamfers.
A brick placing automat takes the fresh bricks from the press and smoothly places them on a hardening car. The Masa press control system enables a precise and space-saving loading of the hardening cars so as to make an optimum use of the autoclave capacity.
When the hardening car has been loaded completely, it is moved to a transport platform via a rail track system. Depending on the factory capacity, up to 8 hardening cars can be moved so that loading and unloading of the autoclaves can be carried out quickly.
From the transport platform, the hardened sand lime bricks are transported to the packaging plant on the hardening cars via a rail track system. To guarantee a fast discharge of the autoclaves, a complete autoclave filling can be stored intermediately in front of the packaging plant.
Masa recommend to package the finished products in that way that they are protected from dirt and moisture before they are removed from the factory. Depending on the plant concept, this packaging process can be carried out automatically or semi-automatically.
modern and sophisticated technologyfully automatic machines for the production of sand lime, AAC and concrete productsdecades of experience from competent expertsworldwide service centersenergetic consulting from planning to realizationreliable supply of spare parts and customer care
Densification of switchgrass into consistent and high-density solid feedstock will reduce the cost of transport, handling, and storage to produce fuels and chemicals. Development a novel, low-cost densification technology is critical for reducing the delivered cost of feedstock while improving the bulk flow properties of densified products. In this paper, a novel wet granulation technology was proposed to investigate the effect of lime pretreatment on the production of switchgrass granules. Granulation is a process of agglomerating fine powders by wetting powder surfaceswith liquid binders and mild application of shear/vibrating forces. Switchgrass was size reduced into fine powders using a knife mill and pretreated with three lime loading rates (0.05, 0.1, 0.2g/g of biomass) at 121C for 30min and at room temperature (25C) for 72h. The structural modification of pretreated samples was analyzed by scanning electron microscopy and autofluorescence microscopy. Pretreated samples were granulated using a pan granulator with pre-formulated starch binder. Granules made from 20% (0.2g/g of biomass) lime loading rate had significantly higher single granule density and angle of repose with lower binder requirement than that of untreated granules. Lime treatment did not significantly increase the bulk density and hardness of granules. Lime-treated granules had significantly higher ash content and lower gross calorific value than that of untreated granules. In overall, lime treatment was not attractive to produce granules for thermochemical conversion platform, but lime-treated granules could be used to produce liquid biofuels and platform chemicals in biochemical conversion platform.
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Sokhansanj S, Mani S, Turhollow A, Kumar A, Bransby D, Lynd L, Laser M (2009) Large-scale production, harvest and logistics of switchgrass (Panicum virgatum L.)current technology and envisioning a mature technology. Biofuels Bioprod Bioref 3(2):124141. doi:10.1002/bbb.129
Donohoe BS, Vinzant TB, Elander RT, Pallapolu VR, Lee YY, Garlock RJ, Balan V, Dale BE, Kim Y, Mosier NS, Ladisch MR, Falls M, Holtzapple MT, Sierra-Ramirez R, Shi J, Ebrik MA, Redmond T, Yang B, Wyman CE, Hames B, Thomas S, Warner RE (2011) Surface and ultrastructural characterization of raw and pretreated switchgrass. Bioresour Technol 102(24):1109711104. doi:10.1016/j.biortech.2011.03.092
Rijal B, Igathinathane C, Karki B, Yu M, Pryor SW (2012) Combined effect of pelleting and pretreatment on enzymatic hydrolysis of switchgrass. Bioresour Technol 116:3641. doi:10.1016/j.biortech.2012.04.054
Xu J, Cheng JJ, Sharma-Shivappa RR, Burns JC (2010) Lime pretreatment of switchgrass at mild temperatures for ethanol production. Bioresour Technol 101(8):29002903. doi:10.1016/j.biortech.2009.12.015
Samuel R, Foston M, Jiang N, Allison L, Ragauskas AJ (2011) Structural changes in switchgrass lignin and hemicelluloses during pretreatments by NMR analysis. Polym Degrad and Stab 96(11):20022009. doi:10.1016/j.polymdegradstab.2011.08.015
Wang Z, Li R, Xu J, Marita JM, Hatfield RD, Qu R, Cheng JJ (2012) Sodium hydroxide pretreatment of genetically modified switchgrass for improved enzymatic release of sugars. Bioresour Technol 110:364370. doi:10.1016/j.biortech.2012.01.097
ASTM (2006) ASTM E 873-82 Standard test method for bulk density of densified particulate biomass fuels. In: Annual Book of ASTM Standards. American Society for Testing and Materials, West Conshohocken, PA, USA
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We acknowledge the financial support provided by the Southeastern Sun Grant Initiative, University of Tennessee, Department of Transportation (DOT) for this research. The authors also thank Dr. M. K. Kandasamy, Director of Biomedical Microscopy, UGA, for training on imaging lime-treated switchgrass using autofluorescence microscopy.
Some operations apply the raw quicklime directly to the ore on the belt moving toward further crushing or grinding. In this application, it is necessary only to have a suitable lime storage tank with a live bin bottom and a means for metering the lime from the tank to the ore. Such metering devices may be screw conveyor, belt conveyor or star valves. An activated bin bottom on the storage tank, commonly referred to as a live bin bottom, is very desirable to promote, uniform discharge from the tank. The lime is thus intimately mixed with the ore and slakes to form hydrated lime when it comes in contact with the cyanide leach solution.
When mill practice requires that the lime first be slaked and made into a water slurry, the design engineer will find a wide variety of lime slakers available. All of these reject most of the inert material in the line except the ball mill slaker which grinds the core, which then reports with the lime slurry. Because of the high reactivity of the lime available, it has been found practical to slake lime in a common steel agitated tank. Slaking temperatures as low as 120F have been found practical, although a slaking temperature in the range of 160F is preferable. The tank slaker may also be used for lime slurry storage if the batch is sufficient to last a desirable time. The slaked batch may be recycled over a screen for rejecting core or the tank may be drained and the core flushed out of the bottom periodically.
When pumping a lime slurry to point of application, it must be borne in mind that calcium hydroxide has an inverse solubility. If the slurry temperature increases during transit, calcium hydroxide will precipitate from solution and scale the walls of the transport line. For this reason, it is common practice to use flexible lines for slurry transport. Much has been published on the handling of lime from kiln to point of use and the design engineer has this information at his finger tips. The use of lime for pH control in gold recovery operations experiences almost no problems and should a problem develop, it is easily solved.
When large quantities of lime, say in the range of 100 tons per day, are required, a captive lime plant has often been considered. If high quality limestone and fuel are readily available near the mill site, the idea of a captive lime plant may seem attractive. However, over the years, captive lime plants have not been very successful. The art and science of lime production is usually not compatible with the chemical process using lime. The occurrence of suitable limestone and fuel on, or near location is the exception rather than the rule. Also, when the raw limestone is crushed to a suitable size for kiln feed, between 20 and 30% of the raw stone must be rejected as quarry screenings. Such screenings find little or no market.
Granulation of sinter feed mix is one of the most important factors in determining the permeability of sinter bed and sinter properties like sinter yield, tumbler index, etc. To improve the granulation of sinter feed mix, various technologies like two-stage granulation process, coating granulation process, wet vertical ball mill and use of magnetic water have been reported. In this paper, effect of pre-heated water (30, 60 and 90C) on granulation fitness of sinter feed mix was studied using a laboratory mixing drum. Sinter properties were investigated using pot sinter experiments. It was observed that with addition of pre-heated water, granulation fitness i.e., Balling index (BI) and Granulation index (GI) has increased, indicating that wetting of sinter feed mix has improved significantly. Treatment of sinter feed mix with pre-heated water reduces the surface tension of water and improves slaking of lime. This enables improved binding of the small size faction (0.25mm), leading to stronger green ball which results in reduced fine generation during charging to the sinter bed. This further leads to the improvement in bed permeability and sinter properties. Enhanced hydration of lime and improved dispersion of water thus achieved have benefitted granulation fitness (GI increases by 5.3% and BI increases by 9.7%). Sinter yield increases by 2.1% and tumbler index by 1.6%. The results suggest that the proposed methodology is effective in improving the granulation fitness of sinter feed mix and sinter properties.
Rajak, D.K., Singhai, M., Sahu, R. et al. Effect of Mixing Pre-heated Water on Granulation and Iron Ore Sinter Properties. Trans Indian Inst Met (2021). https://doi.org/10.1007/s12666-021-02251-4
A microwave fast heating was employed to produce repetitive pattern of V2AlC MAX phase.MAX phase composite was produced through V2O5-Al-C system.V2C MXene was produced by aggressive leaching process.
The present work focuses on the preparation of V2C MXene from Al-V2O5-C mixture heated in a microwave and etched under HF-based process. In the first stage of process, microwave heating caused the formation of an uncommon periodic pattern of V2AlC-Al2O3 MAX phase. In the second stage of process the aggressive leaching (temperature of 80C for 96h) was performed in HF to remove the interlayer aluminum and Al2O3 particles as impurities. The leaching was not completed at room temperature even after 24h. XRD and FESEM analyses confirmed the successful formation of V2C MXene and its distorted layer, respectively. HRTEM, XPS and Raman analyses also confirmed a perfect structure of V2C MXene. It seems that the sintering of compacted Al-V2O5-C mixture in microwave and subsequently aggressive leaching of these samples encourage the formation of periodic pattern of MAX phase together with few-layer V2C MXene. Finally, this work led to the successful preparation of MXene using cheap starting materials and the influence of microwave heating on the reduction of V2O5 by Al which could be a driving force for the formation of periodic pattern in V2AlC.