Grinding plant materials

For solid-liquid extraction, the raw material needs to be ground to the proper size for the extraction equipment used. This shortens the path of diffusion, reducing the required extraction time. In grinding plant materials, the control of fines is very important for many operations. Too many fines can prevent percolation-type extractors from operating properly. In addition, fine material can be carried in the product extract, necessitating their removal by filtration or by using other solid-liquid separation equipment. 

Grinding Plant materials can be homegenized by grinding with acid washed quartz sand (0.5 g/mL) in a mortar and pestle or in a Waring blender. 

Aluminum reduction plants Materials handling Buckets and belt Conveyor or pneumatic conveyor Anode and cathode electrode preparation Cathode (haldng) Anode (grinding and blending) Particulates (dust) Hydrocarbon emissions from binder Particulates (dust) Exhaust systems and baghouse Exhaust systems and mechanical collectors... 

Plant Material - The yellow heartwood was separated from the sapwood of JL, tullplfera and air dried before grinding. Other plant parts (leaf, stem bark, root bark, root, fruit, and flower) were collected, but alcoholic extracts showed no antimicrobial activity. 

Grind the plant material to a fine powder. The finer ground the material the better your yields will be. The best technique to pulverize and rupture the cell structure of any plant material is to repeatedly freeze and thaw it over and over again. An example of a plant requiring this treatment is Phalaris arundinacea, a strong and limber grass. Mimosa hostilis root-bark is easily pulverized to a fine powder in a blender, releasing a pink haze. 

Attrition Mill is an apparatus contg two-sided knives which grind the material very fine by friction. Attrition mills are used at some expls plants, such as Wabash Ordnance Works, For drawings and description, see... 

All cells have to be broken open to remove the cell contents. To accomplish cell lysis the authors use a combination of homogenizing and grinding steps. For recalcitrant tissue a small rock grinder (i.e., ring grinder) is used. The authors advise the experimenter to perform a trial run on their plant material to establish the number and duration of homogenization steps. These should always be the minimum required to break open the cells. Excessive... 

Grinding the plant material in the presence of liquid nitrogen provides a uniform powdered composite sample however, some powdered materials are very hygroscopic. With such materials, it is advisable to accurately weigh the plant material (before freezing) and quantitatively transfer the powdered material with an appropriate solvent. 

For freeze-dried samples, extract the dry sample ( 0.3 to 1 g dry weight starting from 2 to 3 g fresh weight) with diethyl ether and apply the equations given for diethyl ether (UNIT F4.3). Extraction of freeze-dried plant material with diethyl ether is performed by grinding in a mortar. It is also possible to use 80% acetone or 100% methanol, but diethyl ether has proved to be an excellent solvent for quantitative extraction of chlorophylls and carotenoids from freeze-dried plant material. 

Harvest the cellulase-containing transgenic plants at the end of the season (dry), grind this material to release enzyme, and subsequently use it in the enzymatic hydrolysis of lignocellulosic biomass for ethanol production. 

In a small mortar grind 2 g of green or brightly colored fall leaves (don t use ivy or waxy leaves) with 10 mL of ethanol, pour off the ethanol, which serves to break up and dehydrate the plant cells, and grind the leaves successively with three 1-mL portions of dichloromethane that are decanted or withdrawn with a Pasteur pipette and placed in a test tube. The pigments of interest cU e extracted by the dichloromethane. Alternatively, place 0.5 g of carrot paste (baby food) or tomato paste in a test tube, stir and shake the paste with 3 mL of ethanol until the paste has a somewhat dry or fluffy appecu-ance, remove the ethanol, and extract the dehydrated paste with three 1-mL portions of dichloromethane. Stir and shake the plant material with the solvent in order to extract as much of the pigments as possible. 

Some botanical insecticides are made by grinding raw plant materials, such as flowers, roots, stems, or seeds. Others are extracted from plant materials, then refined, purified, and packaged for sale. 

---