Department: Ecology and chemical technology
Speciality: Chemical technology of high molecular connections
Purpose of work is composition and realization of method of research of organic matters, melting and crystallization, drafting and implementation, which have melting temperature less than 1000 oС.
In our work we consider the following organic matters: trinitrotolene, naphthalene, sodium thiosilphate, paraffin and petrolatum; physical-chemical base of melting and crystallization; melting in laboratory conditions; working off the crystallization method in the forms of paraffin and petrolatum melts; analysis of crystallization method in the forms [1].
Trinitrotoluene is a crystalline substance of light yellow colour which is a part of the brisant explosives.
Trinitrotoluene is a fire-dangerous, physically and chemically proof substance. At heating during 100 hours at 1500 oС it does not change its characteristic, temperature of disintegration is 1600 oС. As trinitrotoluene has negative oxygen balance at the moment of explosion the large volume of carbon oxide is produced. It is toxic, causes trinitrotoluene intoxication of organism, irritation of skin and eyes illness.
Naphthalene С10Н8 is a hard crystalline substance with characteristic smell, it is not dissolved in water, but it is well-dissolved in organic substances such as benzol, ether. It distils over with steam.
N. (from greek. naphtha is oil) is aromatic hydrocarbon; temperature of melting is 80,30 oС, temperature of boiling is 2180 oС; volatile, steams at 500 oС; closeness of 1,15-17 g/sm3 (150 oС).
N. by chemical characteristics is similar to benzol: it is azotized and sulphonated easily, reacts with halogens. Differs from benzol by easier reaction.
Sodium thiosulphates are colourless transparent crystals odourless with monoclinic grate; temperature of melting is 48,50 oС; 1,715 g/sm3; brackish-bitter by the taste. The dihydrates and hemihydrates are melted incohruently at 65,5 and 740 oС accordingly and metastable tetra- and geksahydrat.
It dissolves in water (1:1), does not dissolve in an alcohol practically. Hyposulphite is melted at the temperature close to + 500 oС in crystallized water.
Paraffin is a high-similar substance, mixture of boundary carbohydrate (alkanes) of structure from С18Н38 to С35Н72. Temperature of melting is 40-65oС, density is 0,880-0,915 g/sm3 (150 oС). It is produced from the oil essentially [2].
Paraffin is a mixture of methane row with mainly normal structure with 18-35 atoms of carbon in a molecule and temperature of melting of 45-65oC hard hydrocarbons. The amount of isoparaffin hydrocarbon and hydrocarbons with an aromatic or naphthalene kernel in a molecule is usually contained in paraffin.
analysing the properties of the mentioned substances and we chose the method of research of organic substances, melting and crystallization, drafting and implementation such as paraffin and petrolatum. A choice is based on their minimal insecurity and temperature of melting.
Melting is the process of substances transition from the crystalline state to liquid. At the heating of a hard crystalline substance to certain temperature, its temperature remains permanent, and the matter state escapes from hard to wet. This effect is the melting.
A warmth used from the transition of matter from the crystalline state to wet (at the temperature of melting) is the hidden warmth of melting.
Warmth merged by the matter in the process of melting and extracted to environment in the cooling reverse process at the same volume is crystallization [3].
Process of explosives crystallization from the fusion, the trintrotoluene in particular, is not studied enough by this moment. On the basis of practical examinations it is possible to consider that for the multitude of explosives used for an inundation dependence of centers formation of crystallization and linear speed is alike.
So, the speed of growth is greater for crystals with direction of maximal heat-conducting coincided with direction from the wall of shell to the geometrical axis of burster rotation. These crystals disable further growth of neighbouring crystals and spread in the fusion as stake situated perpendicular to surfaces of cooling. Thus, it is issued large crystal construction charge with small sphere created from the small chaotic oriented crystals adjoining directly to the wall of shell.
Making of fusion in laboratory conditions foresees preparatory work related with transfer of technological stream from manufacturing to laboratory conditions. Therefore we elect a paraffin and petrolatum workings matters on the basis of their characteristics (minimal insecurity and the temperature of melting less than 1000 С) and aquatic bath-house as the basic equipment.
An aquatic bath-house consists of electric flag on which a capacity is set from the coloured metal gap-filling water. We place a glass vessel in water and then consistently place batches from different matters for their subsequent melting to it. Near the flag we set the states with claw-holder, where a thermometer with measuring of temperature to 1000 oС is placed [4].
Order of implementation of work:
We start a process with breaking and weighing on batches 100g, 200g, 300g, 400g on technical scales of paraffin. At the same moment vassel with water is set on the heated hotplate and is heating up to the temperature of 1000 oС (temperature of boiling of water). After that first batch of 100g is placed in the boiling water. Watching the process of melting, we fix time of the complete melting of batch and temperature of fusion at this juncture. Melt remained batches by the same way.
Repeat all process for a matter such as petrolatum.
Crystallization of fusions is realized in accordance with the laws of transmission – at first cork, which contacts with the walls of form and layer of solution which contacts with air are formed. Wares were withdrawn from forms for an inundation and tempered after thickness of solution. On the basis of the wares got we conclude that petrolatum thickens for less time, than paraffin, but it is more fragile. Shrinkage shells situated at the wares of paraffin appeared during the process of hardening have more acute angle, and the emergent of shrinkage shell on the surface of petrolatum product causes formation of cracks.
Change of diameters on the height of good we could see from the datas of table is a result of phenomenon such as shrinkage shells. It is also possible to mark a compression near shrinkage shells. Diminishing of volume of SR is in an isolated area which arises up at his consolidation results in formation of shrinkage shells. If an isolated area is small, in the process of consolidation there are not only shells but also areas of mionectic closeness or area of loose structure that we could see after cut of products received.
As result of imperfection of melting setting and not very much high-quality matters, in the understratum of wares pores there are expressly shown gap-filling water. The greater closeness of water explains location of these pors in the understratum of wares.
On the underbody of wares express evidently accumulation of outside admixtures. Also there are such types of shortage, as combs.
Comparing wares we conclude, that paraffin has a dendrite structure of superficial layer, and petrolatum – centre. We could see admixtures constituting matter such as petrolatum which accumulated at the surface.
The producing of DPU
Preparation of water mass for producing of the cast charges and detonator DPU-830 Tl is produced in a mixer for manufacturing flocculent fusion situated in the department of inundation. flocculent fusion consists of fusion of trintrotoluene and its floe [5].
Loading of trintrotoluene floe in a mixer carried out downstream the screen (the diameter of screen is 10mm). Before beginning of research we check up the temperature of water at a mixer shirt (tv=84-980oС), then we close interim valve of the mass conductor of melt supply to the drum of flocculation and open intermediate valve of the mass conductor of melt supply to a mixer. After achievement of fusion level in the mixer of approximately 1/3-1/2 heights a tank (check through the boot hatch of mixer by a wooden oar), block an intermediate valve on an oil pipe-line, include a mixer and add trintrotoluene floes through the stream in a mixer (load of floe is carried out by small portions approximately for 30-35 kg) [6]. Through uninterrupted rotation of mixer we obtain the homogeneous mass. Time of preparation of water mass makes 30-40 minutes, and a temperature of water mass must be 81 - 85oС (assume to reduce the temperature of water mass by addition of new portion of floe). Readiness of the mass is determined by sight, manhole of mixer is closed by the cover with wellington washer, close a valve of air vent, putting on the handle of valve lever a counterbalance (5 kg). For prevention of burns of hands, work is done in mittens. On a signal (of flooder) give the compressed air in a mixer (initial pressure of compressed air 0,15-0,20 mPa, then goes down and remains permanent 0,03-0,08 mPa). The compressed air in a mixer is given with help of valve situated on povitryavodi. Water mass goes to unbottle valve through mass conductor.
The first molten portions of mass unite in bucket and direct to crystallization. Then mass of inundation gets into in special bucket for determination of its readiness (readiness is determined by determination of diameter of spread) the possible lateral altar of density of which is 34-38 cm). To select test directly from a mixer is not accepted.
At the receipt of satisfactory result of verification of mass density, the inundation of detonators is done. An inundation is executed in water instrument which consists of overhead and lower flanciv. Cover of detonator is set on lower flanec, then the pressed sword from A-IX-I is put on pin of lower flancya, after that upper flanec is put on cover. After establishment of water instrument, a tap of water valve is opened and through the windows of centring bush the flood is realized. After completion of the case to the level approximately 40-60 mm from a cut, a valve is closed. Time of extract is 3-5 min and than the filling-up is produced. All of it is carried out together with bringing up of matter in shells. Filling is executed to the lower butt end of flancya. Time of self-control of the inundated detonator is 10 – 15 min. After this disassemble of filling instrument is realized, its cleaning and cleaning of detonators from tailings of trintrotoluene.
Detonators after an inundation is controlled for quality. Control is realized on weight, on original appearance, on passing a caliber of corks. After control detonators and lid is sent to the marking. Marking is inflicted separately on paper step. Step is fastened to the detonator by putting of lid on a shell.
Marking of detonator must contain: number of party, year of producing, factory number of detonator. Also on the lid of detonator must be marked after its producing that must contain: mark of detonator of „DPU-830 Tl”, commodity sign or conditional denotation, enterprise-manufacturer [7].
After marking of detonators tins detonators is packed in corrugated boxes (for 24 sht.). Weight of each box of Detonator is no more 25 kg. Detonators is packed in a box apeak or horizontally, densely by rows (walls a box and interval between the rows are filled by literary garbage). After the putting of detonators in a box, paper gasket is put, a box is closed by metallic valves and clammy ribbon (width of ribbon of 60-100 mm). Before sealing of the box in the place of box interface the market of packer is done. On the side of box labels are glued: from one side – mark, from the other is a sign of danger.
The finished goods are carried out to warehouse by declivous car or tractor with a trailer. A load in transport is carried out by a band conveyer.