Hemp coal

Paulownia charcoal is one of the most superior kinds of carbon particle as a black powder component for producing power, but it is not cheap, and for some time it has been replaced by hemp coal. Recently paulownia coal has recovered its use again because of the decrease in the culture of hemp. 

A black fine powder which has a somewhat hygroscopic feeling. The apparent specific gravity is 0.22g/cc. The dye adsorption power is the largest of all the kinds of plant coal. A mixture of hemp coal, sulphur and potassium nitrate burns to produce a violet flame and less fire dust than pine charcoal. It is used to obtain a large force of explosion as a component of black powder or in combination with potassium chlorate or perchlorate for the bursting charge of chrysanthemum shells. 

It is more hygroscopic than the pine charcoal this may be caused by a phosphorus compound which is found in cultivated plants in general. 

One analysis showed 9.15% moisture and 8.64% ash, and the carbon content may be less than 82%. Such a small carbon content is a defect of this material and the ash contains Si, Cu, K, A1 and phosphorus compounds. 

The wash water(5 grams of hemp coal / 30cc of water) showed a pH value of 10.5, and changes the colour of phenolphthale in to red. The purification of hemp coal by washing it with water takes much time, because the filtration is very slow due to its alkaline nature. The particle size of commercial hemp coal is less than 20 microns, but it is better to sieve it before use to remove foreign matter. 

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Potassium chlorate and hemp coal (77 23 iu weight ratio) 12- 46 ... 

Potassium perchlorate and hemp coal (77 25 in weight ratio) 10 19 ... 

Note (l)The content of the hemp coal shows an.addit ional percent. (2)The line under figures shows the composition which continues burning even under 10 a of water. 

Paulownia charcoal also gives big sparks, especially big willow-like sparks at the end. Pine charcoal gives rather -small sparks, but produces them quite frequently. The sparks from hemp coal are not as good as those from pine charcoal. Household charcoal causes a violent reaction at first and blows away the fire ball substance, and even ff the fire ball is formed,... 

Paulownia charcoal. A light powder, which is easily scattered and has an apparent specific gravity of 0.12 g/cc. This value is the lowest for all the kinds of charcoal at present available. The dye adsorption power in water lies between pine charcoal, and hemp coal which has the largest. One analysis showed that it contained. 9% moisture and 2.5% ash. The pH value of the wash water(5 grams of charcoal / 30cc of water) was 7 5 A mixture of the paulownia charcoal, sulphur and potassium nitrate burns as well as the pine charcoal, but it produces less fire dust than the pine charcoal. 

Manufacture.The following method is typical An oven is constructed with stones in the shape of a well. The inside diameter of the oven is determined so that the hemp caules can be easily inserted. At first some of the hemp caules are ignited and thrown into the oveii, and then the remainder of the caules are heaped on the fire step by step at intervals so that the material thrown in at first does not become ash. Finally, water is poured on the hemp to extinguish the fire. The hemp coal thus produced is dried by itself from the remaining heat. Finally it is crushed to a fine powder and sieved to remove coarse grains and foreign matter. 

Potassium bichromate promotes the burning reaction of potassium perchlorate composition when it is added to it in small amounts. For example, a test showed that the burning rate of a composition which consisted of potassium perchlorate and hemp coal in a weight ratio 75 25 increased 1.55 times when k 3% potassium bichromate was added to it. 

Or a ratio of chlorate to hemp coal of 10 3 is also popular. After many sensitive tests it is known that this is quite unexpectedly insensitive to shock and friction perhaps a little more sensitive than black powder. 

Hemp coal(or paulownia coal) Soluble glutinous rice starch... 

Aluminium (fine flakes) and Hemp-coal were tested. 

Charcoal is insoluble in any chemicals and does not melt. Charcoal, including the hemp coal later described, belong to the so called amorphous carbon allotrope. This material has many atoms in a parallel row. The main fine structure of the carbon is a plate on which carbon atoms are... 

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