JPS58156566A - Lightweight aggregate manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention is made of volcanic ash as a main component, is robust and has low water absorption.
Furthermore, it relates to a method of loading lightweight aggregate with a relatively low firing temperature, and in detail, volcanic ash and a specific binder are kneaded and granulated, and during this granulation, preferably after granulation, the granules are This invention relates to a method for producing lightweight aggregate, which involves absorbing a specific aqueous solution of a media aid, drying it, and then firing it.

Structural aggregates such as cement and mortar, i.e., lightweight aggregates used in construction of walls, floors, columns, etc., have conventionally been made mainly of volcanic ash and powdered clay, which are granulated, dried, and then fired. Lightweight aggregates obtained by

Furthermore, lightweight bones made of volcanic ash and powdered clay as main components, with the addition of borax as a medium or slaked lime instead of borax, are granulated, dried, and fired in the same manner as described above. The material is also known.

However, all of these are aimed at reducing weight, and although they are both excellent in terms of light weight (specific gravity:
1.2 to 1.25), but on the other hand, it lacks robustness, resulting in a decrease in compressive strength (compressive strength of concrete: approximately 270
kW/crlo Based on JIS5002 test method. ) Furthermore, it has a very high water absorption rate of 18 to 24% (measured using the water absorption rate test method described below), so it has drawbacks such as cracks in structures due to freezing, especially in cold regions such as Hokkaido. Moreover, it requires a high firing temperature of 2,500°C or higher.

As a result of repeated research in order to improve the above-mentioned drawbacks existing in the prior art, the present inventor has granulated volcanic ash by kneading a specific binder, and during this granulation, preferably after the granulation. By absorbing an aqueous solution of a specific auxiliary agent into an object, drying it, and then firing it, the firing temperature can be changed to i, o o o ℃ ~ 1,100 ℃.
The present inventors have discovered that lightweight aggregates that are strong and have low water absorption can be obtained at low temperatures, leading to the completion of the present invention.

An object of the present invention is to provide a method for producing a lightweight aggregate mainly composed of volcanic ash, which has excellent robustness (high compressive strength), low water absorption, and a relatively low firing temperature.

In order to achieve the above-mentioned object, according to the present invention, volcanic ash and a binder of the volcanic ash are kneaded and granulated, and an aqueous medium adjuvant solution is absorbed into the granulated material during or after the granulation. and then drying and then firing the granules, the binder being one or a mixture of one or more selected from the group of natural or synthetic resins, gypsum and cement, and the aqueous medium and auxiliary solution is an aqueous solution containing one or more selected from the group consisting of fired glass powder, quartz powder, and carbonated lime powder, and one or more selected from the group consisting of lead oxide, fired borax, and industrial salt. characterized by something.

Hereinafter, the present invention will be explained in detail using the accompanying drawings. FIG. 1 is a schematic diagram showing one specific manufacturing process of the present invention. 01 is a raw material storage section, in which volcanic ash is stored. The volcanic ash is transported from the raw material storage section 1 to the granulator 3 by the belt conveyor 2,
Here, it is thoroughly kneaded with the binder stored in the binder storage tank 4 and granulated.

The binder is one or a mixture of one or more selected from the group of natural or synthetic resins, gypsum, and cement.Specifically, natural resins include lignin, resin, etc., and synthetic resins include, for example. , polyacrylic resin, epoxy resin, polyester, ethylene vinyl acetate copolymer, urethane resin, synthetic rubber latex polymer, vinyl acetate resin, and the like.

Although the mixing ratio of volcanic ash and the binder is arbitrary,
Especially when it comes to natural or synthetic resins, volcanic ash is 85% by weight.
~9o: Preferably the binder is 10-15, and in the case of plaster or cement, volcanic ash 75-8o:
Binding materials 20-25 are preferred.

Next, the granulated material obtained in the above-mentioned process is sent to a dryer 6 via a conveyor 5 to be dried, and further dried at 51 in a Dronmerk.
They are sieved into particle sizes of
The granules are then transported to the granules, where they are sprinkled with an aqueous solvent aid solution and absorbed.

The aqueous medium solution contains one or more selected from the group consisting of fired glass powder, quartz powder, and carbonated lime powder, and one or more selected from the group consisting of lead oxide, fired borax, and industrial salt. An aqueous solution containing, for example, a combination of parts by weight of fired glass powder I, a weighted part of lead oxide, and a weighted part of baked borax, quartz powder (9) parts by weight,
An aqueous solution prepared by dissolving a combination of 40 parts by weight of lead oxide and a weighted part of calcined borax, or a combination of a weight part of carbonated lime powder and a weight part of an industrial base, respectively, in . be.

The above-mentioned granulated material having absorbed the aqueous medium-aid solution is then conveyed into the rotary kiln 11 via the conveyor 10, where it is fired at a firing temperature of 1,000 DEG C. to 1,100 DEG C. for about 5 minutes. In this case, it is preferable that the passage time for the granulated material to pass through the rotary kiln 11 is 15 minutes or more. Thereafter, it is cooled in a cooling kiln 12 to obtain a final product (aggregate). The volume of the final product had shrunk by approximately % compared to before firing.

The water absorption rate and compressive strength of the product (sample) thus obtained were measured. Water absorption rate is JI8A1
It was determined by the 135 test method. That is, first, the sample was thoroughly washed with water to remove dust and other particles on the surface of the grains, and dried at 100 to 110°C until it reached a constant weight.Next, the sample was cooled to room temperature and heated at 15 to 2 S'C. After absorbing water for at least 9 hours in still water, remove the visible water belly on the surface by wiping it off on a highly absorbent cloth to make the surface dry and saturated. It was expressed as Ws as the weight in water state. Continue reading this material for 100-110
After drying at C until it reached a constant weight, it was cooled to room temperature in a desiccator. The weight of the sample at this time was expressed as the weight of the sample after drying by WD.90 Using these Ws and WD, the water absorption rate Q (weight percentage X) was determined by the following formula.

The above test was conducted twice, and the average value is shown below.

The compressive strength is determined by using the aggregate of this product as a cement aggregate according to the JIS 5002 test method.

The results were as follows.

Water absorption: 0.9X or less Compressive strength: 450 Aii'/cr/i or more From the above results, the following can be seen.

The product according to the present invention has a very low absorption rate compared to those of the prior art, and therefore, even if the product is used in cold regions, freezing damage will not occur.

(There will be no cracks in the structure.)0Also,
It has a high compressive strength, almost comparable to natural gravel, and therefore has excellent robustness, making it possible to construct structures with high compressive strength.

Claims (1)

[Claims] 1. Volcanic ash and a binder of the volcanic ash are kneaded and granulated, the granulated material is made to absorb an aqueous solution of a media aid during or after the granulation, and then the granulated material is dried and then fired. characterized in that the binder is one or a mixture of one or more selected from the group of natural or synthetic resins, gypsum and cement, and the aqueous mediating agent solution is one selected from the group of fired glass powder, quartz powder and carbonate lime powder. 1. A method for producing lightweight aggregate, which is an aqueous solution containing one or more selected from the group consisting of lead oxide, baked borax, and industrial salt.