Coal Compound & sand additives1) What should be moisture coal compound. Any specification or standard for that? 2) Theoretically nil, but some will come due to wet saw dust used 3) For high pressure line moisture should be less then 10% free flow coal.bond if I am wrong please correct and for normal.mixture should be 10 - 15% but price is more if you want low moisture material 4) From where this much high moisture is coming in coal compound? Are Manufacturer adding it deliberately or is it a manufacturing process requirements? 5) Basically coal comp hve pitch .good quality coal dust .saw dust and some oils as binder.now moisture comes from saw dust as rightly said but the major problem is the coal which have low ash and pitch during pulverising get heated and in storage they get chared ( only small smoked evolution) in storage.hence storing of the coal compound needs care.now generally the supplier need to store at their godown and ensure that the coal.compound reaches customer at minimum.but safe. according to me generally all coal compound manufacturer keep moisture about 15% to 16% for safety.secondly imported coal dust which I used mainly from 6) According to my knowledge , it is in range 15-17% in coal compound. Vivek - rightly assumed as requirement of manufacturing process. As it can get burned due to internal reactions , it required that much moisture. Other wise will take off fire. If any thing more or any thing wrong pl correct me. 7) According to my knowledge - all coal manufacturers are importing coal and at the time of unloading at port government had made restrictions to all importer to keep the coal cool so that it will not get burning. Government had made an arrangement of water showering on coal. Almost 60 to 70% moisture in raw coal 8) we are getting 14 to 18 % in every batch of receiving , Supplier spec is 15 % max. 9) Moisture must have to control within 10-15%. Lower percent may lead to Charr and higher percentage mean you are bearing additional cost for transportation. 10) High moist may cause loss of money to customer which can be compensate by negotiating with supplier. But else what will be other effect of this high moisture on sand mixing & quality of sand mixing. 10) Moisture in Bentonite or coal dust additive will be almost in fixed range from one supplier (of course commercials are involved). We should concentrate on how to control moisture in return sand. 11) Controlling moisture in coal compound is not a issue. But it's safe to maintain in between 12% min to 18% max in final product. It will be safe to use and not ignite (catch fire) 12) Indonesia are very wet as mentioned by onebof our members and they are become more hygroscopic when turn into dust and hold water upto 14-15% even if is dried to say 10% .also our stdard
moisture estimation requires sample to be dried in lab oven at 110 C .now some components of oil which is used as binder in making coal compound also get volatilize. Hence a normal range of 16-18% is practically accepted.and the price of coal compound is based on these assumption.