A composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand and its application

Abstract

The present invention provides a composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand and its application, belonging to the technical field of thermal insulation materials. The thermal insulation mortar provided by the present invention is composed of the following components: cement, fine aggregate and water, wherein the fine aggregate is porous pottery sand and desert sand, and the porous pottery sand is obtained by sintering arsenic sandstone. The present invention adds porous pottery sand prepared by sintering arsenic sandstone as a thermal insulation material, which has a porous structure, so that the thermal insulation mortar has good thermal insulation performance. At the same time, desert sand and porous pottery sand are compounded, and the particle size and ratio of the two are controlled, which can ensure that the mortar has good strength, so that the thermal insulation mortar can meet the technical requirements, and at the same time, arsenic sandstone and desert sand can be utilized as resources, which is energy-saving and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation materials, and in particular to a composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand and application thereof. Background Art

[0002] Arsenic sandstone is a loose rock formation, concentrated in the Ordos Plateau in the border area of ​​Shanxi, Shaanxi and Inner Mongolia in the northern part of the Loess Plateau of China. Due to its special rock and soil properties, it is very prone to soil erosion, causing great damage to the regional ecological environment. At present, a lot of work has been done on the erosion mechanism and engineering management of arsenic sandstone, which has effectively prevented the further deterioration of the ecological environment in the arsenic sandstone area, but it has also paid a huge price in manpower, material and financial resources. From west to east, Inner Mongolia is distributed with deserts such as Badain Jaran, Tengger, Ulan Buh, Kubuqi, and sandy lands such as Mu Us, Hunshandake, and Horqin. It is one of the main battlefields for the prevention and control of desertification in the country. For this large-scale idle natural resource, it is necessary not only to achieve its ecological governance, but also to make use of its resources, which will produce greater economic benefits than environmental governance.

[0003] The large-scale use of exterior wall insulation mortar in cold and arid areas can effectively promote building energy conservation. Most of the current insulation mortars use polymer materials. For example, the invention patent CN101139185A discloses an insulation mortar, including a polymer styrene-acrylic emulsion, a pure acrylic emulsion or a acetic-acrylic emulsion. However, the use of polymer materials is harmful to the environment. For example, benzoic emulsion is highly volatile and releases harmful substances such as benzene. Pottery sand is sintered from various types of clay, slate, shale, coal gangue and industrial solid waste. It has the effects of light weight and heat preservation, and can replace polymers to prepare insulation mortar. Arsenic sandstone is a loose rock layer. The prior art, such as the invention patent CN118125811A, prepares arsenic sandstone into porous lightweight pottery sand as light fine aggregate. However, porous sandstone with a diameter of less than 0.315 mm is difficult to prepare, so that when porous sandstone is used alone as aggregate, it does not have the continuous gradation of general fine aggregates, resulting in low strength of the thermal insulation mortar and failure to meet technical requirements. Therefore, how to use porous sandstone as an insulation material while making the strength of the thermal insulation mortar meet the technical requirements has become a difficult problem in the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a composite thermal insulation mortar of arsenic sandstone and desert sand and its application. The thermal insulation mortar provided by the present invention has good thermal insulation performance and strength, meets the technical requirements of thermal insulation mortar, and at the same time enables arsenic sandstone and desert sand to be utilized as resources.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a thermal insulation mortar, which is composed of the following components: cement, fine aggregate and water, wherein the fine aggregate is porous pottery sand and desert sand, and the porous pottery sand is obtained by sintering arsenic sandstone; the volume ratio of the cement to the fine aggregate is 1:(2-4); the mass ratio of the water to the cement is 0.65-0.8; the mass ratio of the porous pottery sand to the desert sand is (1.5-2):1; the particle size of the porous pottery sand is 0.315-5 mm; the particle size of the desert sand is 0.075-0.315 mm;

[0007] The porous ceramic sand has continuous gradation; the mass content of each grade in the fine aggregate is: 0.1-0.2% of 2.5-5mm porous ceramic sand, 30-35% of 1.25-2.49mm porous ceramic sand, 10-15% of 0.63-1.249mm porous ceramic sand, and 20-25% of 0.315-0.629mm porous ceramic sand;

[0008] The desert sand has continuous gradation; the mass content of each grade in the fine aggregate is: 25-30% of 0.16-0.315 mm desert sand and 5-10% of 0.075-0.159 mm desert sand.

[0009] Preferably, the bulk density of the fine aggregate is 1117-1488 kg / m 3 .

[0010] The present invention also provides the use of the thermal insulation mortar described in the above technical solution as a thermal insulation material for building exterior walls.

[0011] The invention provides a thermal insulation mortar, which is composed of the following components: cement, fine aggregate and water, wherein the fine aggregate is porous pottery sand and desert sand, and the porous pottery sand is obtained by sintering arsenic sandstone; the volume ratio of the cement to the fine aggregate is 1:(2-4); the mass ratio of the water to the cement is 0.65-0.8; the mass ratio of the porous pottery sand to the desert sand is (1.5-2):1; the particle size of the porous pottery sand is 0.315-5 mm; the particle size of the desert sand is 0.075-0.315 mm; the porous pottery sand has a continuous Grading; the mass content of each grade of fine aggregate is: 0.1-0.2% of 2.5-5mm porous pottery sand, 30-35% of 1.25-2.49mm porous pottery sand, 10-15% of 0.63-1.249mm porous pottery sand, and 20-25% of 0.315-0.629mm porous pottery sand; the desert sand has a continuous gradation; the mass content of each grade of fine aggregate is: 25-30% of 0.16-0.315mm desert sand and 5-10% of 0.075-0.159mm desert sand. The thermal insulation mortar provided by the present invention adds porous pottery sand prepared by sintering arsenic sandstone as a thermal insulation material, which has a porous structure, so that the thermal insulation mortar has good thermal insulation performance. At the same time, desert sand and porous pottery sand are compounded, and the particle size and ratio of the two are controlled, which can ensure that the mortar has good strength and meets the technical requirements of the thermal insulation mortar. At the same time, arsenic sandstone and desert sand can be utilized as resources, which is energy-saving and environmentally friendly. The results of the embodiment show that the thermal conductivity of the thermal insulation mortar provided by the present invention is below 0.2W / (m·K) and the compressive strength is above 23.62MPa. DETAILED DESCRIPTION

[0012] The invention provides a thermal insulation mortar, which is composed of the following components: cement, fine aggregate and water, wherein the fine aggregate is porous pottery sand and desert sand, and the porous pottery sand is obtained by sintering arsenic sandstone; the volume ratio of the cement to the fine aggregate is 1:(2-4); the mass ratio of the water to the cement is 0.65-0.8; the mass ratio of the porous pottery sand to the desert sand is (1.5-2):1; the particle size of the porous pottery sand is 0.315-5 mm; the particle size of the desert sand is 0.075-0.315 mm;

[0013] The porous ceramic sand has continuous gradation; the mass content of each grade in the fine aggregate is: 0.1-0.2% of 2.5-5mm porous ceramic sand, 30-35% of 1.25-2.49mm porous ceramic sand, 10-15% of 0.63-1.249mm porous ceramic sand, and 20-25% of 0.315-0.629mm porous ceramic sand;

[0014] The desert sand has continuous gradation; the mass content of each grade in the fine aggregate is: 25-30% of 0.16-0.315 mm desert sand and 5-10% of 0.075-0.159 mm desert sand.

[0015] Unless otherwise specified, the present invention has no particular limitation on the sources of the components, and commercially available products or conventional source products known to those skilled in the art may be used.

[0016] The thermal insulation mortar provided by the invention comprises cement.

[0017] In the present invention, the cement preferably comprises 42.5 ordinary Portland cement; the bulk density of the cement is preferably 1200-1400 kg / m 3 , more preferably 1300kg / m 3 ; The initial setting time of the cement is preferably >45min; The final setting time of the cement is preferably <12h; The 28d compressive strength of the cement is preferably ≥42.5Mpa; The 28d flexural strength of the cement is preferably ≥6.5Mpa. The present invention limits the various parameters of cement within the above range, which can make the thermal insulation mortar have a suitable construction time and at the same time make the thermal insulation mortar have better compressive strength. In the present invention, the cement is preferably PO.42.5 ordinary Portland cement produced by Inner Mongolia Jidong Cement Co., Ltd.

[0018] The thermal insulation mortar provided by the invention also includes fine aggregate.

[0019] In the present invention, the volume ratio of cement to fine aggregate is 1: (2-4), preferably 1: 3. The present invention limits the volume ratio of cement to fine aggregate within the above range, which can further improve the thermal insulation performance and compressive strength of the thermal insulation mortar.

[0020] In the present invention, the particle size of the fine aggregate is preferably 0.075~5mm; the fine aggregate preferably has a continuous gradation, and the mass content of each grade of fine aggregate is preferably: 2.5~5mm 0.1~0.2%, 1.25~2.49mm 30~35%, 0.63~1.249mm 10~15%, 0.315~0.629mm 20~25%, 0.16~0.3149mm 25~30% and 0.075~0.159mm5~10%. The present invention adopts fine aggregate with continuous gradation, which can make the aggregates fill each other to form a dense structure, so that the thermal insulation mortar has good compressive strength. The present invention limits the continuous gradation of fine aggregate and the mass content of each grade of fine aggregate within the above range, which can further improve the compressive strength of the thermal insulation mortar.

[0021] In the present invention, the fine aggregate is porous pottery sand and desert sand.

[0022] In the present invention, the mass ratio of the porous ceramic sand to the desert sand is (1.5-2):1.

[0023] In the present invention, the particle size of the porous ceramic sand is 0.315-5 mm.

[0024] In the present invention, the porous ceramic sand has a continuous gradation; the mass content of each grade in the fine aggregate is: 0.1-0.2% of 2.5-5 mm porous ceramic sand, 30-35% of 1.25-2.49 mm porous ceramic sand, 10-15% of 0.63-1.249 mm porous ceramic sand, and 20-25% of 0.315-0.629 mm porous ceramic sand; preferably: 0.12-0.18% of 2.5-5 mm porous ceramic sand, 30-33% of 1.25-2.49 mm porous ceramic sand, 12-14% of 0.63-1.249 mm porous ceramic sand, and 21-24% of 0.315-0.629 mm porous ceramic sand.

[0025] In the present invention, the particle size of the desert sand is 0.075-0.315 mm.

[0026] In the present invention, the desert sand has a continuous gradation; the mass content of each grade in the fine aggregate is: 25-30% of 0.16-0.315 mm desert sand and 5-10% of 0.075-0.159 mm desert sand; preferably: 26-28% of 0.16-0.315 mm desert sand and 6-9% of 0.075-0.159 mm desert sand.

[0027] In the present invention, the bulk density of the porous ceramic sand is preferably 590-1000 kg / m 3 .

[0028] In the present invention, the porous ceramic sand is obtained by sintering arsenic sandstone.

[0029] In the present invention, the method for preparing the porous ceramic sand preferably comprises the following steps:

[0030] (1) adding water to a mixture of arsenic sandstone and biomass material to granulate to obtain green balls;

[0031] (2) Sintering the green ball obtained in step (1) to obtain porous ceramic sand.

[0032] In the present invention, water is preferably added to the mixture of arsenic sandstone and biomass material for granulation to obtain green balls.

[0033] In the present invention, the arsenic sandstone is preferably loose arsenic sandstone. In the present invention, the arsenic sandstone is preferably loose arsenic sandstone in the Ordos region.

[0034] In the present invention, the arsenic sandstone is preferably subjected to a first screening to obtain an undersize component, drying, ball milling and a second screening to obtain an undersize component in sequence before use.

[0035] In the present invention, the sieve opening during the first sieving is preferably 2-3 mm, more preferably 2.36 mm.

[0036] The present invention has no particular limitation on the drying temperature and time, and any drying technical solution well known to those skilled in the art may be used.

[0037] In the present invention, the ball milling time is preferably 1-2 hours, more preferably 1.5 hours; the grinding balls during the ball milling are preferably steel balls; the rotation speed of the ball mill is preferably 300-500 rpm, more preferably 400 rpm; the ball-to-material ratio during the ball milling is preferably (1-2):1, more preferably 1.5:1.

[0038] The present invention has no special limitation on the equipment for the ball milling, and any ball milling equipment known to those skilled in the art can be used. In the present invention, the ball milling equipment is preferably a planetary ball mill.

[0039] In the present invention, the average particle size of the arsenic sandstone after the second screening is preferably 5-6 μm, more preferably 5.46 μm. The present invention limits the average particle size of the arsenic sandstone to the above range, so that the subsequent sintering can be carried out more fully.

[0040] The present invention has no particular limitation on the type of the biomass material, and any biomass material known to those skilled in the art may be used. In the present invention, the biomass material preferably includes one or more of corn stalks, corn cobs, and wheat stalks. In the present invention, the biomass material acts as a skeleton during the initial granulation period, and volatilizes during the subsequent sintering process to form pores.

[0041] In the present invention, the biomass material is preferably dried and pulverized in sequence before use.

[0042] The present invention has no particular limitation on the drying temperature and time, and any drying technical solution well known to those skilled in the art may be used.

[0043] In the present invention, the average particle size of the biomass material is preferably 30-35 meshes, more preferably 32 meshes. The present invention has no special limitation on the operation of the pulverization, and the technical scheme of pulverization well known to those skilled in the art is adopted to ensure that the average particle size of the biomass material after pulverization is within the above range. The present invention limits the average particle size of the biomass material to the above range, and volatilizes to form pores during the subsequent sintering process, so that the porous ceramic sand has a suitable pore size, further improves the thermal insulation performance of the thermal insulation mortar, and makes the thermal insulation mortar have better strength.

[0044] In the present invention, the mass ratio of the biomass material to the arsenic sandstone is preferably (0.1-20): 100, and more preferably (5-20): 100. The present invention limits the mass ratio of the biomass material to the arsenic sandstone within the above range, so that the pottery sand has a suitable porosity, further improves the thermal insulation performance of the thermal insulation mortar, and makes the thermal insulation mortar have better strength.

[0045] In the present invention, the ratio of the mass of water to the total mass of arsenic sandstone and biomass material is preferably (25-30): 100, more preferably 28: 100. The present invention limits the amount of water to the above range, which is more conducive to the granulation process.

[0046] In the present invention, the water is preferably added in the form of atomized water. The present invention has no particular limitation on the formation of atomized water, and a technical solution well known to those skilled in the art can be used.

[0047] In the present invention, the rotation speed during granulation is preferably 40-60 rpm, more preferably 50 rpm; the granulation time is preferably 10-20 min, more preferably 15 min. The present invention limits the rotation speed and time during granulation to the above range, which is more conducive to obtaining green balls.

[0048] After obtaining the green ball, the present invention preferably sinters the green ball to obtain porous ceramic sand.

[0049] In the present invention, the green ball is preferably dried before sintering.

[0050] In the present invention, the moisture content of the green ball after drying is preferably ≤2%. In the present invention, the drying temperature is preferably 60-120°C, more preferably 110-120°C; the present invention has no particular limitation on the drying time, as long as the moisture content of the green ball after drying reaches the above range. In the present invention, the drying can improve the strength of the green ball and facilitate subsequent sintering.

[0051] In the present invention, the sintering preferably includes a first sintering, a second sintering and a third sintering performed sequentially.

[0052] In the present invention, the holding temperature of the first sintering is preferably 600-700°C, more preferably 650°C; the holding time of the first sintering is preferably 15-20min, more preferably 20min; the heating rate from room temperature to the holding temperature of the first sintering is preferably 10-20°C / min, more preferably 15-20°C / min. The present invention can remove bound water from the minerals in the green ball through the first sintering, and a solid phase reaction occurs between the feldspar minerals and the metal cations, gradually transforming from a single substance into a mixed substance of sodium feldspar, potassium feldspar and calcium feldspar; and the biomass material is decomposed by heat to produce a large number of pore structures, and the ceramic sand system has an initial skeleton; because the system needs to absorb a large amount of heat for dehydration, it needs to be kept warm for a period of time at this stage.

[0053] In the present invention, the insulation temperature of the second sintering is preferably 1100-1130°C, more preferably 1100-1125°C; the insulation time of the second sintering is preferably 20-50min, more preferably 30min; the heating rate from the insulation temperature of the first sintering to the insulation temperature of the second sintering is preferably 15-20°C / min, more preferably 20°C / min. The present invention decomposes calcium carbonate in the system by heat through the second sintering to release carbon dioxide; the solid phase of feldspar and quartz minerals gradually transforms into liquid phase eutectic, and liquid phase substances in the system are gradually generated; this stage is mainly a crystal reaction between minerals, and the process is relatively slow. The present invention controls the insulation time to make the overall heating uniform and the reaction more complete.

[0054] In the present invention, the temperature of the third sintering is preferably 800-900°C, more preferably 800°C; the cooling rate from the second sintering holding temperature to the third sintering temperature is preferably 5-10°C / min, more preferably 5°C / min. The present invention can prevent the green body from cracking due to excessive cooling rate at the above cooling rate.

[0055] In the present invention, after sintering, the material is preferably cooled with the furnace and then sieved to obtain porous ceramic sand.

[0056] The present invention has no special limitation on the operation method of the screening, and a conventional screening method can be used to ensure that the particle size of the porous ceramic sand after screening is within the above range.

[0057] The present invention preferably obtains porous ceramic sand of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm and 0.315-0.629 mm respectively through screening.

[0058] In the present invention, the desert sand includes 0.16-0.315 mm and 0.075-0.159 mm desert sand. The present invention preferably sieves the desert sand to obtain desert sand with particle sizes of 0.16-0.315 mm and 0.075-0.159 mm, respectively. The present invention has no special limitation on the sieving operation, and the sieving technical solution well known to those skilled in the art can be used.

[0059] In the present invention, the desert sand is preferably the Kubuqi desert sand in the Ordos region.

[0060] In the present invention, the moisture content of the desert sand is preferably less than 2%. When the moisture content of the desert sand is not within the above range, the present invention preferably dries the desert sand. The present invention has no special limitation on the drying operation, and a drying technical solution well known to those skilled in the art can be used to ensure that the moisture content is within the above range.

[0061] In the present invention, the bulk density of the fine aggregate is preferably 1117~1488kg / m 3 The present invention limits the bulk density of fine aggregate within the above range, which can further improve the compressive strength of the thermal insulation mortar.

[0062] The thermal insulation mortar provided by the invention also includes water.

[0063] In the present invention, the mass ratio of water to cement is 0.65-0.8, preferably 0.7-0.75. In the present invention, the consistency of the thermal insulation mortar is preferably 70-90 mm. The present invention limits the mass ratio of water to cement within the above range, so that the mortar has a suitable water-cement ratio, and the mortar has suitable fluidity, which meets the construction requirements.

[0064] The thermal insulation mortar provided by the present invention adds porous pottery sand prepared by sintering argillaceous sandstone as a thermal insulation material, and the mortar has a porous structure, so that the thermal insulation mortar has good thermal insulation performance. At the same time, desert sand and porous pottery sand are compounded, and the particle size and ratio of the two are controlled, which can ensure that the mortar has good strength and meets the technical requirements of the thermal insulation mortar. At the same time, argillaceous sandstone and desert sand can be utilized as resources, which is energy-saving and environmentally friendly.

[0065] In the present invention, the method for preparing the thermal insulation mortar preferably comprises: mixing cement, fine aggregate and water to obtain the thermal insulation mortar.

[0066] The present invention has no special limitation on the mixing operation of the cement, fine aggregate and water. A technical scheme for mixing materials well known to those skilled in the art can be adopted to ensure that the components are mixed evenly.

[0067] The present invention also provides the use of the thermal insulation mortar described in the above technical solution as a thermal insulation material for building exterior walls.

[0068] The present invention has no special limitation on the application operation of the thermal insulation mortar, and the application technical solutions familiar to those skilled in the art can be adopted.

[0069] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] Example 1

[0071] (1) After passing the loose arsenic sandstone (loose arsenic sandstone in the Ordos area) through a 2.36 mm sieve, it was dried in an electric hot air drier, and then placed in a planetary ball mill for 1.5 h. The grinding balls were steel balls, the rotation speed was 400 rpm, and the ball-to-material ratio was 1.5:1. The ball-milled powder was then taken out and sieved to obtain arsenic sandstone with an average particle size of 5.46 μm;

[0072] (2) drying the discarded corn cobs in an electric heated air drying oven, and then crushing the discarded corn cobs to an average particle size of 32 meshes to obtain corn cob powder;

[0073] (3) mixing the arsenic sandstone obtained in step (1) and the corncob powder obtained in step (2) (the mass ratio of corncob powder to arsenic sandstone is 5:100), placing the mixture in a blender for stirring, and then placing the mixture in a round pot granulator at a rotation speed of 50 rpm. During the rotation, atomized water is added (the mass ratio of atomized water to the total mass of arsenic sandstone and corncob powder is 28:100), and granulation is performed for 15 minutes to obtain green balls;

[0074] (4) The green ball obtained in step (3) is dried at 100°C until the moisture content is less than 2%, and then sintered. The sintering process is specifically as follows: heating from room temperature to a first sintering holding temperature of 650°C, holding for 20 minutes, and a heating rate of 20°C / min; then heating from 650°C to a second sintering holding temperature of 1125°C, holding for 30 minutes, and a heating rate of 20°C / min; then cooling from 1125°C to a third sintering temperature of 800°C, and a cooling rate of 5°C / min; then cooling to room temperature in the furnace and sieving to obtain porous ceramic sand with particle sizes of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm, and 0.315-0.629 mm, respectively, and with a bulk density of 910.9 kg / m 3 , 957.2kg / m 3 、964.6kg / m 3 , 976.2kg / m3 .

[0075] Example 2

[0076] (1) After passing the loose arsenic sandstone (loose arsenic sandstone in the Ordos area) through a 2.36 mm sieve, it was dried in an electric hot air drier, and then placed in a planetary ball mill for 1.5 h. The grinding balls were steel balls, the rotation speed was 400 rpm, and the ball-to-material ratio was 1.5:1. The ball-milled powder was then taken out and sieved to obtain arsenic sandstone with an average particle size of 5.46 μm;

[0077] (2) drying the discarded corn cobs in an electric heated air drying oven, and then crushing the discarded corn cobs to an average particle size of 32 meshes to obtain corn cob powder;

[0078] (3) mixing the arsenic sandstone obtained in step (1) and the corncob powder obtained in step (2) (the mass ratio of corncob powder to arsenic sandstone is 10:100), placing the mixture in a blender for stirring, and then placing the mixture in a round pot granulator at a rotation speed of 50 rpm. During the rotation, atomized water is added (the mass ratio of atomized water to the total mass of arsenic sandstone and corncob powder is 28:100), and granulation is performed for 15 minutes to obtain green balls;

[0079] (4) The green ball obtained in step (3) is dried at 100°C until the moisture content is less than 2%, and then sintered. The sintering process is specifically as follows: heating from room temperature to a first sintering holding temperature of 650°C, holding for 20 minutes, and a heating rate of 20°C / min; then heating from 650°C to a second sintering holding temperature of 1125°C, holding for 30 minutes, and a heating rate of 20°C / min; then cooling from 1125°C to a third sintering temperature of 800°C, and a cooling rate of 5°C / min; then cooling to room temperature in the furnace and sieving to obtain porous ceramic sand with particle sizes of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm, and 0.315-0.629 mm, respectively, and with a bulk density of 773.7 kg / m 3 、754.7kg / m 3 、765.9kg / m 3 、779.4kg / m 3 .

[0080] Example 3

[0081] (1) After passing the loose arsenic sandstone (loose arsenic sandstone in the Ordos area) through a 2.36 mm sieve, it was dried in an electric hot air drier, and then placed in a planetary ball mill for 1.5 h. The grinding balls were steel balls, the rotation speed was 400 rpm, and the ball-to-material ratio was 1.5:1. The ball-milled powder was then taken out and sieved to obtain arsenic sandstone with an average particle size of 5.46 μm;

[0082] (2) drying the discarded corn cobs in an electric heated air drying oven, and then crushing the discarded corn cobs to an average particle size of 32 meshes to obtain corn cob powder;

[0083] (3) mixing the arsenic sandstone obtained in step (1) and the corncob powder obtained in step (2) (the mass ratio of corncob powder to arsenic sandstone is 15:100), placing the mixture in a mixer for stirring, and then placing the mixture in a round pot granulator at a rotation speed of 50 rpm. During the rotation, atomized water is added (the mass ratio of atomized water to the total mass of arsenic sandstone and corncob powder is 28:100), and granulation is performed for 15 minutes to obtain green balls;

[0084] (4) The green ball obtained in step (3) is dried at 100° C. until the moisture content is less than 2%, and then sintered. The sintering process is specifically as follows: heating from room temperature to a first sintering holding temperature of 650° C., holding for 20 min, and a heating rate of 20° C. / min; then heating from 650° C. to a second sintering holding temperature of 1125° C., holding for 30 min, and a heating rate of 20° C. / min; then cooling from 1125° C. to a third sintering temperature of 800° C., and a cooling rate of 5° C. / min; then cooling to room temperature in the furnace and sieving to obtain porous ceramic sand with particle sizes of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm, and 0.315-0.629 mm, respectively, and with a bulk density of 717.9 kg / m 3 、721.6kg / m 3 、725.5kg / m 3 、768.9kg / m 3 .

[0085] Example 4

[0086] (1) After passing the loose arsenic sandstone (loose arsenic sandstone in the Ordos area) through a 2.36 mm sieve, it was dried in an electric hot air drier, and then placed in a planetary ball mill for 1.5 h. The grinding balls were steel balls, the rotation speed was 400 rpm, and the ball-to-material ratio was 1.5:1. The ball-milled powder was then taken out and sieved to obtain arsenic sandstone with an average particle size of 5.46 μm;

[0087] (2) drying the discarded corn cobs in an electric heated air drying oven, and then crushing the discarded corn cobs to an average particle size of 32 meshes to obtain corn cob powder;

[0088] (3) mixing the arsenic sandstone obtained in step (1) and the corncob powder obtained in step (2) (the mass ratio of corncob powder to arsenic sandstone is 20:100), placing the mixture in a blender for stirring, and then placing the mixture in a round pot granulator at a rotation speed of 50 rpm. During the rotation, atomized water is added (the mass ratio of atomized water to the total mass of arsenic sandstone and corncob powder is 28:100), and granulation is performed for 15 minutes to obtain green balls;

[0089] (4) The green ball obtained in step (3) is dried at 100°C until the moisture content is less than 2%, and then sintered. The sintering process is specifically as follows: heating from room temperature to a first sintering holding temperature of 650°C, holding for 20 minutes, and a heating rate of 20°C / min; then heating from 650°C to a second sintering holding temperature of 1125°C, holding for 30 minutes, and a heating rate of 20°C / min; then cooling from 1125°C to a third sintering temperature of 800°C, and a cooling rate of 5°C / min; then cooling to room temperature in the furnace and sieving to obtain porous ceramic sand with particle sizes of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm, and 0.315-0.629 mm, respectively, and with a bulk density of 594.3 kg / m 3 、683.8kg / m 3 、687.7kg / m 3 、692.9kg / m 3 .

[0090] Example 5

[0091] (1) Desert sand (Kubqi desert sand in Ordos region) was dried to a moisture content of less than 2% and then sieved to obtain desert sand with particle sizes of 0.16-0.315 mm and 0.075-0.159 mm respectively;

[0092] (2) The porous ceramic sand prepared in Example 1 and the desert sand obtained in step (1) are mixed to obtain fine aggregate, wherein the porous ceramic sand has a continuous gradation, and the mass content of each grade in the fine aggregate is 0.16% for 2.5-5 mm porous ceramic sand, 30.99% for 1.25-2.49 mm porous ceramic sand, 12.43% for 0.63-1.249 mm porous ceramic sand, and 22.61% for 0.315-0.629 mm porous ceramic sand; the desert sand has a continuous gradation, and the mass content of each grade in the fine aggregate is 26.62% for 0.16-0.315 mm desert sand and 7.19% for 0.075-0.159 mm desert sand; the bulk density of the fine aggregate is 1391 kg / m 3 ;

[0093] (3) 42.5 ordinary Portland cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3, initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate obtained in step (2) are mixed in a volume ratio of 1:3, and then water is added and mixed evenly (the mass ratio of water to cement is 0.7), and the consistency is 73 mm to obtain thermal insulation mortar.

[0094] Example 6

[0095] (1) Same as Example 5;

[0096] (2) The porous ceramic sand prepared in Example 1 in step (2) of Example 5 is replaced by the porous ceramic sand prepared in Example 2. At this time, the bulk density of the fine aggregate is 1222 kg / m 3 , other parameters are the same as those in step (2) of Example 5;

[0097] (3) 42.5 ordinary Portland cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3 , initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate obtained in step (2) are mixed in a volume ratio of 1:3, and then water is added and mixed evenly (the mass ratio of water to cement is 0.75), and the consistency is 71 mm to obtain thermal insulation mortar.

[0098] Example 7

[0099] (1) Same as Example 5;

[0100] (2) The porous ceramic sand prepared in Example 1 in step (2) of Example 5 is replaced by the porous ceramic sand prepared in Example 3. At this time, the bulk density of the fine aggregate is 1211 kg / m 3 , other parameters are the same as those in step (2) of Example 5;

[0101] (3) 42.5 ordinary Portland cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3 , initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate obtained in step (2) are mixed in a volume ratio of 1:3, and then water is added and mixed evenly (the mass ratio of water to cement is 0.8), and the consistency is 84 mm to obtain thermal insulation mortar.

[0102] Example 8

[0103] (1) Same as Example 5;

[0104] (2) The porous ceramic sand prepared in Example 1 in step (2) of Example 5 is replaced by the porous ceramic sand prepared in Example 4. At this time, the bulk density of the fine aggregate is 1117 kg / m 3 , other parameters are the same as those in step (2) of Example 5;

[0105] (3) 42.5 ordinary Portland cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3 , initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate obtained in step (2) are mixed in a volume ratio of 1:3, and then water is added and mixed evenly (the mass ratio of water to cement is 0.8), and the consistency is 73 mm to obtain thermal insulation mortar.

[0106] Comparative Example 1

[0107] (1) Fine aggregate is obtained by continuous grading of standard sand. The mass content of continuous grading and each grade is 0.16% of 2.5-5 mm standard sand, 30.99% of 1.25-2.49 mm standard sand, 12.43% of 0.63-1.249 mm standard sand, 22.61% of 0.315-0.629 mm standard sand, 26.62% of 0.16-0.3149 mm standard sand and 7.19% of 0.075-0.159 mm standard sand. The bulk density of fine aggregate is 1683 kg / m 3 ;

[0108] (2) Cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3 , initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate in step (1) are mixed in a volume ratio of 1:3, and then water is added (the mass ratio of water to cement is 0.65) to obtain a mortar with a consistency of 71 mm.

[0109] Comparative Example 2

[0110] (1) Loose arsenic sandstone (loose arsenic sandstone in the Ordos area) was sieved through a 2.36 mm pore sieve to obtain a screening component, which was dried in an electric hot air blower dryer and then placed in a planetary ball mill for 1.5 h. The grinding balls were steel balls, the rotation speed was 400 rpm, and the ball-to-material ratio was 1.5:1. The ball-milled powder was then taken out and sieved to obtain arsenic sandstone with an average particle size of 5.46 μm;

[0111] (2) The arsenic sandstone obtained in step (1) is placed in a mixer and stirred, and then placed in a round pot granulator. The rotation speed of the granulator is 50 rpm. Atomized water (the mass ratio of atomized water to arsenic sandstone is 28:100) is added during the rotation process. Granulation is carried out for 15 minutes to obtain green balls;

[0112] (3) The green ball obtained in step (2) is dried at 100°C until the moisture content is less than 2%, and then sintered. The sintering process is specifically as follows: heating from room temperature to a first sintering holding temperature of 650°C, holding for 20 minutes, and a heating rate of 20°C / min; then heating from 650°C to a second sintering holding temperature of 1125°C, holding for 30 minutes, and a heating rate of 20°C / min; then cooling from 1125°C to a third sintering temperature of 800°C, and a cooling rate of 5°C / min; then cooling to room temperature in the furnace and sieving to obtain ceramic sand with particle sizes of 2.5-5 mm, 1.25-2.49 mm, 0.63-1.249 mm, and 0.315-0.629 mm, respectively, and with a bulk density of 964.3 kg / m 3 、977.8kg / m 3 , 984.6kg / m 3 , 996.2kg / m 3 .

[0113] Comparative Example 3

[0114] (1) Desert sand (Kubqi desert sand in Ordos region) was dried to a moisture content of less than 2% and then sieved to obtain desert sand with particle sizes of 0.16-0.315 mm and 0.075-0.159 mm respectively;

[0115] (2) The pottery sand prepared in Comparative Example 2 and the desert sand obtained in step (1) are mixed to obtain fine aggregate, wherein the pottery sand has a continuous gradation, and the mass content of each grade in the fine aggregate is 0.16% of 2.5-5 mm pottery sand, 30.99% of 1.25-2.49 mm pottery sand, 12.43% of 0.63-1.249 mm pottery sand, and 22.61% of 0.315-0.629 mm pottery sand; the desert sand has a continuous gradation, and the mass content of each grade in the fine aggregate is 26.62% of 0.16-0.315 mm desert sand and 7.19% of 0.075-0.159 mm desert sand; the bulk density of the fine aggregate is 1488 kg / m 3 ;

[0116] (3) 42.5 ordinary Portland cement (Inner Mongolia Jidong Cement Co., Ltd., bulk density 1300kg / m 3, initial setting time of 160 min, final setting time of 385 min, 28d compressive strength of 48.7 MPa, 28d flexural strength of 8.1 MPa) and the fine aggregate obtained in step (2) are mixed in a volume ratio of 1:3, and then water is added and mixed evenly (the mass ratio of water to cement is 0.7), and the consistency is 87 mm to obtain mortar.

[0117] According to JGJ / T 70-2009 "Standard for Test Methods for Basic Properties of Building Mortar", the compressive strength, consistency and apparent density of the mortars in Examples 5 to 8 and Comparative Examples 1 and 3 were tested; according to GB / T 10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Insulating Materials - Guarded Hot Plate Method", the thermal conductivity of the mortars in Examples 5 to 8 and Comparative Examples 1 and 3 was tested using a DR3030 thermal conductivity tester produced by Shanghai Rongjida Instrument Technology Co., Ltd. The results are shown in Table 1.

[0118] Table 1 Consistency, compressive strength, apparent density and thermal conductivity of mortar in Examples 5 to 8 and Comparative Examples 1 and 3

[0119]

[0120] As can be seen from Table 1, the thermal insulation mortar provided by the present invention has a lower thermal conductivity, better thermal insulation performance, and better compressive strength, and can meet the technical requirements of building exterior wall plaster mortar.

[0121] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand, consisting of the following components: Cement, fine aggregate and water, wherein the fine aggregate is porous pottery sand and desert sand, and the porous pottery sand is obtained by sintering arsenic sandstone; the volume ratio of the cement to the fine aggregate is 1:(2-4); the mass ratio of the water to the cement is 0.65-0.8; the mass ratio of the porous pottery sand to the desert sand is (1.5-2):1; the particle size of the porous pottery sand is 0.315-5 mm; the particle size of the desert sand is 0.075-0.315 mm; The porous ceramic sand has a continuous gradation; the mass content of each grade of the porous ceramic sand in the fine aggregate is: 0.1-0.2% of 2.5-5 mm porous ceramic sand, 30-35% of 1.25-2.49 mm porous ceramic sand, 10-15% of 0.63-1.249 mm porous ceramic sand, and 20-25% of 0.315-0.629 mm porous ceramic sand; The desert sand has continuous gradation; the mass content of each grade of the desert sand in the fine aggregate is: 25-30% of 0.16-0.315 mm desert sand and 5-10% of 0.075-0.159 mm desert sand; The preparation method of the porous ceramic sand comprises the following steps: (1) adding water to a mixture of arsenic sandstone and biomass material for granulation to obtain green balls; the average particle size of the arsenic sandstone is 5-6 μm; the biomass material includes one or more of corn stalks, corn cobs and wheat stalks; the average particle size of the biomass material is 30-35 meshes; the mass ratio of the biomass material to the arsenic sandstone is (0.1-20):100; (2) Sintering the green balls obtained in step (1) to obtain porous ceramic sand; drying the green balls before sintering; cooling the green balls with the furnace after sintering, and then screening to obtain porous ceramic sand.

2. The composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand according to claim 1, characterized in that: The bulk density of the fine aggregate is 1117~1488kg / m 3 .

3. Use of the composite thermal insulation mortar of arsenic sandstone pottery sand and desert sand as claimed in any one of claims 1 to 2 as a thermal insulation material for building exterior walls.

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