Process for reinforcing geological formations

BACKGROUND OF THE INVENTION The present invention relates to a process for the consolidation of geological formations and of rock and earth masses.

A process is known for sealing and strengthening geological formations Against water or gases, with the help of polyurethane, which essentially consists in that the reaction components forming with the group -NH-CO-O- a cross-linked product, namely a di- or plyliocyanate, and a polyol having at least three groups — OH reagents, mixed together in a liquid carrier material (carrier), it is injected under pressure into the form to be sealed or strengthened.

Toluylene diisocyanate or toluene diisocyanate prepolymers and compounds are recommended as di- or polyisocyanates. _2ţJpolyhydroxyls, such as castor oil or hexanthrol. Some disadvantages are inherent to these compounds, which make it difficult or impossible to use them under the ground. Thus, toluene diisocyanate has a relatively high vapor pressure and²⁵damage to human mucous membranes, especially the respiratory organs. The toluene-diisocyanate prepolymers have a high viscosity and, generally, insufficient storage stability. They must be processed almost without exception together with liquid materials-suppo.rt, such as soaps or plasticizers. The liquid support materials decrease the flash point of the mixtures and decrease the resistance of the forming polyurethanes.

In order to avoid the mentioned disadvantages of toluene-diisocyanate, for the casting resins more and more such polyisocyanates have been used in recent years, which besides 4,4'-diisocyanate-diphenylmethane contain mainly polyphenyl-polymethylene polyisocyanates. These mixtures of polyisocyanate, referred to in the international literature as MDI, have the disadvantage of being used for the purpose of consolidating the geological formations and of the masses of rock and soil that are incompatible with the usual polyhydroxyl compounds, such as dust and dust. 3-minute stirring of MDI with polyhydroxyl compounds is required, while at too short a stirring time there is a danger of separation.

The usual way of preparing polyurethane to overcome incompatibility

MDI with polyhydroxyl compounds, by increasing the reactivity of the mixture due to the addition of catalysts, such as e76264

LAW PRICE 13.48

70 284 For example, tertiary amines or metallic compounds, cannot be exceeded when consolidating geological famines, as well as rock and earth masses, because the mixture of polyisocyanate and polyhydroxyl compound must remain after mixing for sufficient time. infiltrate into the cracks and pores of the formation that must be strengthened before the solidification or harmful increase of viscosity occurs. Mixtures of poly-iocyanate-polyol without the addition of said catalysts also have a short processing time,¹ barely enough for consolidation purposes. And what the second possible chemical way, to reduce the incompatibility of MDI with the polyols by preparing prepolymers, is not indicated for consolidation purposes, since the prepolymers have a too high viscosity.

The process according to the invention eliminates the above disadvantages, in that it uses as a polyisocyanate component a mixture of polyisocyanate containing 10. . . 80% by weight 2,4'-diisocyanato-diphenylmethane.

Several examples of embodiments of the invention are given below.

Example 1. The polysisocyanates and polyols used in this example and in the other two examples, were noted for reference as follows: '

Isocyanate 7 - A polyisocyanate, consisting of 60% by weight 2,4'-drizocyanato-diphenylmethane and 40% by weight 4,4'-diisocyanato-diphenylmethane. NCO content = 32.8%; viscosity == 13 mPa at 25 ° C,

Isocyanate 2 - A polyisocyanate consisting of 30% by weight 2,4'-diisocyanato-diphenylmethane, 43% 4,4'-diisocyanate-diphenylmethane, 11% di- (isocyanate-phenyl-methyl) -isociangtobenzene and 16% polyphenyl-pollenethylene -poiiizdcidhăţi with the bigger core. NCO content = 32.0%; viscosity - 72 mPa s at 25 ° C. 'r

Isocyanate 3 - A polyisocyanate, consisting of 3% 2,4'-diisocyanato-diphenylmethane, '54% AA'-diisocyanate-diphenylmethane 24% d- (isocyanate-phenylmethyl) - isocyanatoberizen and 19% polyphenyl-polyethylene-polyethylene. bigger. NCO content - 31.8%; viscosity = 75 mPa s at 25 ° C.

Polyol 7 - A polyol polyether, prepared with trimethylolpropane and propene oxide, with an index 0 (4 of 370, an average molecular weight of 450 and a viscosity of 700 m Pa s at 25 ° C.

Polyol 2 - A polyol swab, prepared from glycerin and propylene oxide, with an OH index of I10, an average molecular weight4 of 480 and a viscosity of 620 mPa s at 25 ° C.

Polyol 3 - Castor oil, a natural product that is obtained by coring with the indication of quality by pressing, with an 'OH' of 148 and a viscosity of 930 mPa s at 25 ° C.

Pofio! 4 - A polyol suction cup, prepared from ethylene - diamine and propylene oxide, with an OH index of 61, with an average molecular weight of 3,500 and a viscosity of 630 mPa s at 25 ° C.

As a means of production for rock consolidation, a mixing metering plant is used for the processing of synthetic components with two components, which is composed of the following main components:

A. Two steel storage tanks with a capacity of 30 I. Storage tanks may be closed and may be subjected to a compressed gas inlet to create a preliminary pressure.

β. Two piston metering pumps, which have a common pneumatic drive and which take the material which is under preliminary pressure in the storage tanks in the volumetric ratio of 1: 1 and drive them into a mixer with continuous operation (C).

C. Continuously functioning mixer, formed as a static mixer, consisting of cm steel pipe 70 cm long, an outside diameter of 9.5 mm, an inside diameter of 8.1 mm and 54 plates of sheet metal, mounted in the inside of the pipe and arranged evenly along it.

The mixing metering system works with an exhaust of 2 l / min of the mixture. One of the two storage tanks (A) remains full during the entire working time with polyol 7, the caustic being added 5% by weight alumosilicate sodium of the zeolite type, finely dispersed, by energetic stirring. The second of the two storage tanks (A) is filled at operation 1 with isocyanate'1, at operation 2 with isocyanate 2 and at operation 3 with isocyanate 3,

As a material for consolidation, a 20 cm high rock filling of gravel with a large grain is used, as a grain size of 5 up to 40 mm. for the purpose of consolidation, the outlet of the mixer with continuous operation (C) was kept directly on the¹ more like stone / thus, the mixture of polyisocyanate / polyol, penetrating from top to bottom filled the empty spaces with stones. '

After 5 hours after stopping the mixing dosing plant, the consolidation was evaluated. your^f operation 1 and 2 the material for consolidation was entirely homogeneous and strong. At operation 3 the material

76gȘ4 pertţruru ςοηεο | ΐς | αΓθ 9 was both Iq the highest seat, and at the lower layer Irpqj, soft. Even ρηρ the light pressing of the finger, the law between the market and the q, q in time, during operations 1 and 2, even at a large request was not able to break the stones formed connection.

Ε ^ ΦρΙηΙ?, A two-fold arpsteption is used, consisting of qcmEteprqle parts fPIPPPnpnțp:

A- Rpup storage tanks,

B. Two gear pumps with gear wheels, each with electric drive, '

The dosage ratio should be adjusted to the desired size, with the help of mechanical transmissions with continuous (no steps) adjustment of the turquoise.

C. Mixer with continuous operation, which consists of a cqpnpqrțim^ent cylindrical stirring, with a length of 37 mm and a diameter of 16 mm. In the shaft of the cylinder is mounted a stirrer with pin provided with electric drive, with Iqngimpq of 36 mm, CP i> stirring blades, qp width of about 3^mm ş <ippșimeg d^e14 mm.

The mixing metering system adjusts for a mixing ratio of 1 parts of vplum, component of pp | iisocyanate Iq 1.2 parts d^e volume of polyol composition. Speed ​​of qmpștecqrp P $ qq of 9000 rpm, and the discharge rate is 1 | / hand.

The component of the pulley is inserted into the rpzeryorp | by dePQzitp.re respeqțîv (A), a mixture consisting of djq WP parts Jn grewtfltP polyol 2.20 parts by weight polyol 3 and 10 wt.% by weight of a paste of 50% alumpsiliCat sodium of the type of castor oil in castor oil. As a component of polyisocyanate and ppyl fqlpseșc after oRul '^zPPIQnates 1 ... 3, Pențfu fqp l'Pit's assessment of the polyisocyanate / polyp repulsive mixtures on coal and rock, are broken in the form of coal spines, respectively qrdesian prisms with dimensions 4 X 4 X ^cIhh the fragments attach Iq a small dq 2 mm between the breaking surfaces in a farm and pour over the mixture of pofiococyanate / polyol, which comes out of the hole of the mixing chamber. After a brief interview, you will be interviewed. by bh $ e determines fPFistepțg Jq prevents the paste pfțșmplpjr and is given as a measure q of the lipfrq capacity. The obtained results are presented by Yăqâîpnjl country:

<td>l / qciqnţit</td><td>Cppqcițațșq ffp bonding pq pqrbunq, MPq</td><td>£ apqcitoțeq de l'Rire. pp m? q, lylPq</td>

<td> 0</td><td> ’ 1</td><td>_? .</td>

<td> 1</td><td> 1,24</td><td> 3,10</td>

<td> 2</td><td>n? 8</td><td> 2,65</td>

<td>• Λ •. 4</td><td> 0,31</td><td> 0,26</td>

Example 3. A mixture of polyols was prepared by mixing 1QQ parts by weight polyol 1, 25 parts by weight pqliol 4 and 1.2 parts by weight water. 1QQ g of this mixture of powders were mixed with 1QQ g of isocyanate 1 in a plastic beaker using an electrically operated mixer, whose shaking blade has a length of 6 cm and a width of 2 cm, Ier ovitezq mixing of? 00 rpm for 25 hours.

The mixture was poured into a mine hole inclined downwards, with a diameter of 2 cm and a depth of 50 cm, which was drilled into the hole in the same area with the quill of a rock drill. Immediately after filling, the handpiece was gstupgțq pp a rubber stopper · Pupa 15 h, the plastery rock was violently smashed with qjuțprpl to a sharpened tip. It is found that the polyurethane foam ^ q penetrated from the borehole pp q soft diffusion many centimeters in the cracks of the cold and the gheqsfa g fp§ț soldered and then spliced ​​solid joint. -Before visual observation and pipqjre cp the tip of a pile of sticks! Se. cpnștgță cq in the tightness of ppliuretan there are no inhomogeneities. Cazulη If the sample is run in the same way with dpps?^{in the} the place of the isocyanate 1 is used in the same waters and in the czntifpte jzpcignațld 3, the bumps and the blisters. p fqrtg sticking half a thousand ρ φ the urn of pqljurețpn sij₍ yes, tpritq prpduce.ni of separations, PPI'ÎIUP! '^ fȘPmpipt scattered.

In the following details of the invention,

The essential component of pqliizocignsf fqjpșită, cpnfprrp of the invention, is eqnștițyîr t of dust coatings |_/4 '- dizqqanqto-difepilme-T tqn of 10, 80% by weight, preferably 15,._r8J%&gt; greum

In addition to the 2,4'rjzomet'z sliding component of pqliizpciqnat, according to the invention, how much is generated) _e| azj izqmefi, respectively polyisocyanates homoljșgj from Șj diffig difenflmetqnu / aL Apegșfq: it means that, according to the invention, the cpmppnenfa eWiăiă is constituted in the genera), either from mixtures formed φη diisocyanate-diphenylmethane and 4-diphenylmethane or 20% by weight, based on the total mixture, of 2,2'-diisocyanato-diphenylmethane, either of mixtures of these isomers with polyphenyl-polymethylene - polyisocyanates with the larger nucleus. In the latter mixtures there is generally a content of 10 to 60% by weight, relative to the total mixture, of this kind of polyisocyanates with the larger nucleus. The suitable mixture initially referred to as a polyisocyanate component to be used, according to the invention, can be obtained, for example, by distilling a mixture of the diisocyanate with the said composition, from a mixture of polyisocyanate, as produced by phosphenation of the aniiine / formaldehyde condensates. .³

The mixture containing polyisocyanates with the larger nucleus, also indicated for the process according to the invention, can be obtained by. for example, by mixing the distillation product with a phosgene product depleted in 4,4'-diisocyanato-diphenylmethane.

It is also possible to obtain such a mixture, in other words a mixture of polyisocyanate, whose contents of 2,4'-diisocyanato-diphenylmethane correspond to the essential limits, according to the invention, directly through the proper regulation of the aninine condensation. / formaldehyde;

By the phosphenation of some rich condensates. In 2,4'-diamino-d -phenylmethane polyisocyanates which can be used according to the invention can be obtained directly. In principle, it is possible, without being preferred, to use MDI fractions rich in 2,4'-diisocyanato-diphenylmethane, in combination with other polyisocyanates, such as, for example, foluene-diocyanates.

Polyol components are considered in the process according to the invention, in principle compounds known for the preparation of polyurethanes for other uses, such as polyester! containing groups -OH, polyethers containing groups¹-OH, polyalcohols and oil. Castor. Particularly suitable are polyethers' containing OH groups, prepared from polyalcohols or / amines, as. for example, glycerin, trimethylolpyrrole, ethylene glycol, propylene glycol, ethylenediamine and oxides of olefins such as ethylene oxide and propylene oxide with an OH index of 50 to 600; that also mixtures · of these, precurm and castor oil. The quantity report to be mixed with the isocyanate polyol can be varied within limits. latgij preferably, · is introduced: both isocyanate, · as long as an OH group returns 0.5 ... 2, preferably 0.7 ... 1.5 NCO groups. If the geological formations, as well as the masses of rock and earth that are exposed, contain much moisture, a large excess of isocyanate will be used.

In addition to this, it is possible to use the usual additives known in polyurethane chemistry, for modifying polyurethanes obtained, for example driving agents, such as water, fluorinated hydrocarbons, accelerators, such as tertiary amines, metal catalysts and foam regulators, such as foam regulators. organosilicon compounds. In addition, it is possible to add water-retaining substances, such as sodium aluminosilicate of the zeolite type, if the foaming of the consolidating material is to be avoided. These additives are generally mixed with the polyol component.

When executing the process according to the invention, the reaction mixture, which must produce polyurethane as a result of the reaction, is preferably introduced into pre-prepared mine holes, which, after introducing the reactant mixture, preferably stop, before the chemical reaction. to take greater proportions. Such a stop (closure) of the mine hole is especially recommended, if by the use of the water at the same time, respectively if due to the presence, the water in the geological formation that had to be consolidated, respectively by the use at the same time of the to the organic training agents, a foaming of the reactant mixture is produced. The reaction mixture used, according to the invention, which after the reaction produces polyurethanes, can be introduced in different ways into the geological formation, respectively. In the previously prepared mine hole.

For example, the reaction mixture may be prepared by mixing outside the geological formation and be introduced into it before the reaction begins. Another possibility is that polyisocyanate and polyol components. eg either from separate containers into the handheld, using pumps or pre_:gas seals, in which case the mixing of the two products takes place, for example, in a buffer mixer, which is mounted in front of or inside the mine hole.

Q possibility; Particularly interesting. executing the process according to the invention; consists of the use of a cartridge, the two compartments, 'consisting' of a dbuă. separate tanks · between 'elb, - which, in one dim tank is found! the polyisocyanate component and in the other reservoir there is a polyol component. Here,

ί) the quantity of the two components is so measured, that, after the combination by the destruction of the cartridge, a mixture is born, which by reaction leads to a polyurethane. At the execution of the process, according to the invention, by using such cartridges, they are inserted into the mine hole executed previously and there they are mechanically destroyed for the purpose of mixing the two components. In particular 10, this form of execution proves to be advantageous, if both components are undoubtedly compatible with each other, given that an intensive mixing of the two components 15 after the cartridges are destroyed is almost impossible.

The advantages of the process according to the invention are the following:

The essential component of polyisocyanate 20 used according to the invention, in admixture with all current polyhydroxyl compounds, can be introduced after extremely short mixing intervals in the cracks, cavities and pores of the formations, which need to be strengthened and the mixtures they have enough time to penetrate even the smallest branches and cracks and produce after mechanical solidification resistance ₃₀nice and very good and especially the polyurethanes that produced the cohesion of a defective geological formation are absolutely protected from the occurrence of separation. In addition, the polyurethanes prepared for the use of such polyisocyanates, which bring about the consolidation of the geological formations or of the masses of rock and earth, have the advantage of a strong adhesion on coal and rocks. 40