DE19539684A1 - Self-hardening backfill material prodn. - Google Patents

Abstract

Prodn. of a self-hardening, rock salt-resistant, pumpable backfill material comprises (a) mixing, in predetermined volumetric ratio, at least three different residue materials selected from the groups of (i) cohesive dusty combustion residues which exhibit no reactivity and setting properties, (ii) powdery residues with pozzolanic properties and (iii) granular to lumpy inert material, together with a salt solution consisting of at least four salt components; (b) maturing for more than 10 mins. to less than 4 hrs.; and then (c) introducing the mixture through a pipeline into a rock salt cavity, the mixture remaining pumpable for \-15 hrs. and setting pozzolanically to a solid body in the cavity. Also claimed is apparatus for carrying out the above process.

Description

The invention relates to a method and a device for Production of a pumpable and then hardening Substitute for salt and potash mines. The offset is resistant to mineral salts more commonly, in Kaligruben precom type and training, in particular the easy decomposition carnallite.

With the method according to the invention can from mining own and foreign granular to powdery mineral minerals nature and saline solutions of various kinds and concentrations tration pumpable batching substances of specific consistency be placed over a pipeline to the underground ge promotes and in the ascended in salt rock mining Cavities are pumped. The first flowable to plasti The offset mass fills the cavities entirely or largest partly solidified and hardened in these to a solid body, the after solidification both of the salt rocks Side walls (joints) as well as the ceiling (hanging) of the hollow space and also reflects the effects of rock pressure stands. The device according to the invention consists of a System of individual apparatus, which ver to a total system are bound and ensure that the required property th of the offset good constantly, even with short-term own fluctuations and the large number of input materials be achieved from a wide variety of attacks (residues).

The prior art includes both offset building materials for Coal and ore mining as well as for backfilling of mining cavities in the salinar of potash mines and salt miners ken. According to DE 40 00 183 is a plastically deformable building material known for creating Danes in underground mining, the from filter ash, binder and ground waste art  material in which the plastic deformability by Plastic part is used. Such a building material is suitable mainly for backfilling the expansion in the hard coal lenbergbau and is not suitable as deformation-stable Ver Substance in salinar.

An off-set for potash and salt mines is in DE 42 09 986 described, however, only in the Schleuderversatzverfahren can be introduced and by subsequent pressing and sheathing the surface layers by resin and / or art substance-like masses in the contact area with the salt rock is solidified. According to DE 42 09 987 an offset material is made Contaminated residues from industrial recycling pro described the alkaline residues and residues be mixed from the salt production and overburden salts. salt Residues are part of the offset in this process material itself, must therefore either in an ongoing reduction be mixed under or over days or at a standstill laid mine by dumping extra for this purpose ge to be won. Other components of an offset are to DE 42 13 119 Sludges from water treatment, art substances and waste residues from potash and salt mining. Here, no cement is required as a binder, as the Iron manganese sludge hydraulically setting properties ent wrap.

The use of additional binding materials is possible. Also In this case again overburden residues are as offset component required. Saline solutions, absorbent plastic waste and further additives and binders form according to DE 42 22 830 the material basis of an offset building material, wherein Abrasion salts are added to the pump property and the Abbindefähigkeit the offset to control. DE 42 35 032 describes a method according to which a Magnesium chloride and other salts containing spent liquor, together MgO, an inert additive in the form of industrial Residues, shredder residues or plastics and water  free residues from a waste incineration and possibly clays too a pumpable and later hardening offset mixed become.

The described offset substances of several components who the produced in mixing plants, which is essentially to the state of the art for concrete production and related Lean against mixed processes. Mixing plants of conventional design for Her Construction materials are based on the compilation of Equipment for mixing a few solids with consistent chemical and physical properties with water.

Mixing plants for the production of a dry end product from various residues and binders are under Einbe extraction of silos, conveyor technology, dosing technology and mixers operated.

These plants are not designed for the production of suspen a variety of residues with different chemical and physical properties with addition of potassium hydroxide solution with different salt concentrations and chemical composition.

They do not guarantee the reaction to the temporal behavior th of the suspension, in particular with regard to the other Transport through pipelines to the destination.

Existing equipment is not so with ancillary equipment equipped that the specific properties of the residues in concerning the nature and extent of impurities would be.

A disadvantage of the use of conventional mixing plants for Production of offset building materials from residues is that these are designed for substances with constant properties,  while industrial residues do not meet quality standards and have strongly changing properties.

This is especially true when such offsets without Ab Room salts or salt residues as fillers only on the basis of industrial dusts, incineration ashes and Altsan Change the residue suspensions and salt solutions the composition, Haldensickerlaugen and other components to be produced.

The object of the invention is a manufacturing method for a pumpable offset construction material mining for the offset cavities in Salinar and only on the use powdered, granular and proportionally even wet mine residual residues without the addition of salt residues and stockpiles and saline solution during the pumping process neither mixed nor hardened and only after the Einbrin hardened into the mining cavity by itself. On Another object of the invention is to provide a ge suitable device.

The invention is intended to solve the problem, from diverse Residues of a mineral nature in the form of dust to powder shaped granular to lumpy substances and a saline solution as a carrier liquid containing the components KCl, NaCl, MgCl₂ and MgSO₄ or CaCl₂, an initially mushy and thus To produce a pumpable mixture, this state over a maintains a defined time, neither solidifies prematurely still segregated, and after being introduced into the salt rock be sensitive cavities spreads self-leveling and in hardened to a solid body. The mixture is allowed with do not react to the salt rock and do not dissolve salts Double salts such as carnallite (KCl MgCl₂ 6H₂O) decompose.

Under the influence of gravity or rock pressure may not larger amount of fluid phase are squeezed out.  

Likewise, the problem to be solved, a Versatzbaustoff with as constant as possible pumping and hardening based on substances of varying composition to produce by a suitable device.

It was surprisingly found that against salt rocks and Carnallite stable stakes based on dust shaped residues from industrial incinerators, Ashes and dust-like combustion products, old sands Foundries and other granular to lumpy aggregates alone and without the aid of salt residues and without With the help of a binder can be made, if one as liquor a stock liquor of a potash residue Halde or a waste liquor of a potash processing process and instead of a binder, a pozzolanic one in saline solutions setting residue used. It was found that from a residue in the form of a coarse-grained sandy, a further powdery to dusty residue and pozzolanic acting further combustion dusts and a multicomponent saline solution over at least 15 hours can form flowing paste, which thereafter in the further Course without destruction of adjacent salt rocks to one solid body hardens. Essential for this behavior is a co-use of a pozzolanic residue in the form a waste incineration dust containing CaO and / or CaCl₂ and the use of a saline solution containing at least the Components MgCl₂, MgSO₄, KCl and NaCl and which with CaO or / and CaCl₂ a poorly soluble substance (magnesium hydroxide and / or gypsum).

In this mixture fillers in the form of coarser san Diger to lumpy residues involve a breiar tiger high-consistency fabric, this consistency over a period of 15 hours and above. because through the mushy substance mixture in the mining can Cavity be pumped in salt rock, fill this and self-sustained over a period of several days to weeks  Decisive is the simultaneous presence of a Saline solution with the components MgCl₂-MgSO₄-KCl-NaCl and a Waste incineration dust or flue dust with active CaO and / or CaCl₂, with the components of as Anmachflüssig saline solution used to form sparingly soluble Reaction products reacts.

The offset mixtures are based in principle on inert and pozzolanic Substances of mineral origin, which are replaced by fol The following residue groups can be characterized:

• 1. cohesive, dusty residues (residues from burning planning processes)
• 2. powdery residues with pozzolanic properties, ins special selected CaO / CaCl₂-containing waste incineration dusting
• 3. Inert materials
  grainy to powdery
  lumpy.

The mixing liquid is at least four salt components verwen th containing solution with KCl, NaCl, MgCl₂ and MgSO₄ det. Instead of MgSO₄ can also calcium chloride in the solution to be available.

Salts in solid form are no more necessary than usual Binders such as cement or magnesia binder. The basic components are divided into groups of substances and in different Silos are stacked separately and dosed out of these and taken mixed. Such separately available substance groups are:  

Substance group 1

Filter dusts and RGR salts from waste incineration plants, domestic waste heat and power plants, special waste incineration plants, indu strassenstaububen with inert properties.

Substance group 2

Pozzolans, filter dusts from waste incinerators, filters dusts from steelworks with high CaO content, filter dusts / Bed ashes from coal burning plants, hydraulic setting dusts, non-hydraulic setting dusts with CaO and / or CaCl₂ contents <10%.

Substance group 3

powdery inert

• - Sewage sludge ash
• - sewage sludge drying products

Grainy inerts

• - foundry old sands
• - granular waste products from industrial processes (Slag)

lumpy inert

• small piece material of 1 to 30 mm grain size, which is chemically inactive and no reactions with the other substances.

In addition, as inert substances in a certain amount can also pasty substances such as precipitation and galvanic sludge, Neutralisa sludges, earthy substances from sediments co-used if it does not have the pumping or hardening properties th adversely to be changed, which bestä by experiments is.  

This material mixture must be without interruption in a da be made for suitable plant. The outside of the Salzbergbaues operated thick matter offset is based on the Basis, a mixture of solids and water in Ver 70 to 90% to 30 to 10% with the help of a piston pump to push into underground cavities, with the disadvantage that the cavities must be prepared by mining to the Implementation of the thick matter tube to ensure safety Afford.

For the purpose of the invention, the problem must be solved, a to create a technical facility that is a suspension of a Variety of residues with different chemical and physical properties and in particular saline solution can produce different composition and thereby the further recovery of the suspension, after the hydraulic Transport in possibly long pipelines, as offset material in ensures underground cavities.

Surprisingly, it is possible that such an offset Building material from residues with changing properties without the associated caking in one Mixing plant of conventional design can be produced if the in Property groups divided substances from different Silos simultaneously in volumetrically measured proportions and with the also volumetrically metered saline solution and / or the proportionate residue suspension continuously in the mixer mixed, continuously digested by a stirrer and be held in suspension, while a substance-dependent dwell time kept and the consistency of the mixture over one Density measurement is set, as well as a maturation period before Entry into the pipeline is specified. Was continued found that the mixture production despite the stoffspezi fish usual strong material caking in a konti Continuously working continuous mixer for a long time without Faults and deviations from the given recipe can be performed when the inlet funnel is divided into two  and having an inlet ring nozzle system which is liquid generated at high pressure, on the one hand on the Inlet funnel of the mixer as well as on parts of the mixer are directed for cleaning salt solution and / or Water is used in the production of the substance mixed can be used.

The selection and the spatial allocation of the equipment ensure the mixing process and the continuing digestion of the mixture in a stirred tank under consideration different residence times.

By the density measurement of the suspension and the automatic React the plant to the addition of the mixed components the untimely solidification of the suspension in the pipeline prevented. The solidification takes place in the cavity through the chemical binding of the liquid.

The properties of the residues lead without the invention moderate device features for material caking, esp dere in the mixer. Adapted auxiliary equipment minimize the Manual effort to clean, but eliminate the reason additional defect is not.

With the invention it is achieved that residues in a ge closed system dust-free with water or other salt solutions or proportionate Residualsuspensionen to a Sus pension can be mixed as an offset material in the Salt mining can be used. The suspension is in egg ner generated such quality that to be displaced großflä up to almost 100 percent of their volume be filled without weakening the host rock.  

embodiments Example 1

From silos the following substance groups are de-stored and with the mixing liquid salt solution in the following volume behaves Mixed:

- Substance group 1 20.00% by volume - substance group 2 4.00 vol.% - Substance group 3 @ powdery 5.00 vol.% grainy 6.00 vol.% - Mixing liquid 65.00% by volume

The following overview is a compilation of example Adhere to averages and their fluctuations in the respective Groups of substances.

Halden liquor from a Kalialthalde is used as salt solution, which has the following composition:

The substances are measured volumetrically, mixed and thereby maintained a maturation time of 1.2 to 1.5 hours.

The preparation of the mixture is carried out in the apparatus shown in Fig. 1, consisting of several storage silos ( 1 ), volumetric metering devices ( 2 ), a continuous union continuous mixer ( 3 ), a mixing and maturation vessel with stirring elements ( 4 ) and a tub ( 5 ) and a slurry pump ( 6 ) and measuring and control devices and actuators in pipelines.

After specification of a specified recipe, the individual Residues volumetrically via rotary valves, the liquid via a pump, metered fed to the mixer. The amounts are stored for verification.

In a mixer downstream of the container is the festival substance in the suspension by a stirrer continued up closed and held in suspense. The container serves the same early as a buffer for the following established pump for Transport the suspension to the shaft.

By the density measurement of the suspension in the outlet line is computer-aided the supply of the individual substances so ge controls that a constant suspension is generated, the fulfills the given purpose. The flow behavior of the suspen The study will be based on a Density, the pump pressure, the flow rate of the mixture and  the power consumption of the stirring device, the one-phase the agitator drive is detected, shown. In Auswer tion, the control takes place by adding the individual substances.

example 2

The following recipe components are taken from silo plants and mixed in the apparatus arrangement shown in FIG. 1 to form an offset mixture:

- Substance group 1 15.00% by volume - substance group 2 5.00 vol.% - Substance group 3 @ powdery 4.00 vol.% granular / lumpy 6.00 vol.% pasty 10.00% by volume - Mixing liquid 60.00% by volume

From the three groups of substances (cohesive, dusty residues; Residues with pozzolanic properties and inert substances) can according to the formulas following middle together be presented:

The make-up liquid is a highly concentrated salt solution used from the carnallite processing, the following Zu composition has:

A maturation time of 1.4 to 1.8 hours is set, which rea by a residence time of the mixture in a container is lisiert.

The preparation of the mixture takes place in the FIG. 1 dargestell th mixing plant, which takes into account the material concerns.

The material-related growth of the inlet funnel at the mixer was by a two-piece funnel construction, where the bottom cone in diameter larger than the top running is, and an associated at the transition point ring nozzles system prevented. About the ring nozzle system takes place simultane- ously tig the addition of the liquid.

The hopper inlet is out of the original condition centered to the axis of the sling in the spin direction ver sets to caking material at the leading edge to reduce.

The device features according to the invention are shown in FIG. 2 it clearly.

Claims (9)

1. A process for producing a self-hardening, resistant to salt rock pumpable Versatzstoffes of several mineral residues and a salt solution as Anmachflüssigkeit, characterized in that minde least three different residues from different groups, substance group 1 cohesive dust-like residue substances from combustion processes without reactivity and setting properties, substance group 2 powdery residual materials with pozzolanic properties, substance group 3 granular to lumpy inert materials and a salt solution consisting of at least four salt components are mixed in a given before volume ratio, then ei ner maturing time of <10 minutes at <4 hours are subjected and then via a pipe in the cavities to be displaced are introduced into the salt rock, remain pumpable for at least 15 hours and harden in the filled cavity to a solid body pozzolanic. 2. The method according to claim 1, characterized in that as pozzolanic substances of substance group 2, CaO and / or CaCl₂-containing combustion ash and / or Flue dust from flue gas cleaning processes with a CaO or CaCl₂ content <10 mass% can be used. 3. The method according to claim 1 and 2, characterized that as Anmachflüssigkeit a at least four Kom components containing saline with the components KCl- NaCl-MgCl₂-MgSO₄ or KCl-NaCl-MgCl₂-CaCl₂ is used. 4. The method according to claim 1 to 3, characterized that the multicomponent used as Anmachflüssigkeit Saline solution from a saline dung thickener eye Potash tailings pile with a density of 1.10 to 1.18 g / cm³.   5. The method according to claim 1 to 4, characterized that the multicomponent used as Anmachflüssigkeit Saline solution from a carnalite anfal lumi- ness repellent of the carnallite processing process with a density of 1.25 to 1.34 g / cm³. 6. The method according to claim 1 to 5, characterized that incurred in the cleaning of the mixing device Rinse used in the preparation of the mixture becomes. 7. A process for the preparation of a self-hardening, resistant to salt rocks pumpable Versatzstoff be, consisting of material silos for powdery, granular to lumpy substances, storage tanks for salt solutions, volume and / or weight dosing for solid and liq sige substances, mixing equipment, pumps , Measuring, control and actuator, characterized in that this mixing plant consists of technical equipment, which assemble as a plant to ensure that from one or more residues with the addition of mixing liquid before a given suspension is mixed, the material as Versatzmate in underground Cavities and that the acceptance and storage of dusty residues ( 1 ), the volumetric metering ( 2 ), the continuous mixing ( 3 ), the further digestion and the maintenance of the suspension, taking into account a stoffgebunden NEN residence time ( 4 ) Storage ( 5 ) and the dosing te delivery of the suspension ( 6 ) are continuously possible in a row, equipped with a guaran stet that the suspension can be prepared according to predetermined recipes from defined amounts of one or more residues with metered addition of Anmachflüssigkeit from a ZENTRA len control room , And that the proof of the amount of the individual input materials and the final product is possible at any time. 8. A device for producing a self-hardening, resistant to salt rocks pumpable batch according to claim 7, characterized in that the material-related growth of the inlet funnel at the mixer by a two-part funnel construction ( 7 ), wherein the lower cone is made larger in diameter than the upper, and a ring nozzle system ( 8 ) assigned to the transition point is prevented and the addition of the liquid takes place simultaneously via the ring nozzle system. 9. Apparatus for production according to claim 7 and 8, characterized in that cleaned by directed individual nozzles ( 9 ) with high pressure water parts of the mixer shaft.