JPS6042259A - Plasticity improvement treatment for crushed rock debris - 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 relates to a method for improving the plasticity of a crushed stone layer containing fine particles such as clay and silt and having high consistency.

In the process of open-pit mining of rock and crushing it to produce crushed stone, a crushed stone layer containing topsoil, soft stone, etc. It is essential to separate crushed rock from good quality rock and dispose of this crushed rock layer.

This kind of crushed stone layer has a high consistency because it contains many fine particles such as clay, and when the moisture content increases, it becomes plastic and becomes like a highly plasticized material or fluid, and its supporting capacity becomes extremely small. It is also difficult to use it as a civil engineering material for building land or building land, and it requires a great deal of cost and labor to dispose of it.

In other words, when disposing of waste, consideration must be given, such as adding a large amount of rock to improve the properties, and as a result, the amount of waste to be disposed of increases even more, and dams, etc. are built in valleys etc. for sedimentation treatment. This is common and is a cause of pressure on the profitability of crushed stone layers.

Conventionally, there is a method of physically separating and removing fine particles using such a crushed stone layer. However, there is a method of sieving the fine particles. In the former case, the equipment and processing costs for treating the turbid water containing fine particles used in the washing process increase, and the reality is that it is difficult to dispose of fine clay particles with high moisture content recovered from the turbid water. It is. The latter method is not economical because it requires a lot of heat energy and also requires the cost of collecting dust to prevent the dry dust from scattering.

Therefore, most of the crushed stone waste is disposed of with great effort.
It was hoped that they could be used effectively and at low cost.

In view of the actual situation in the north, the present inventors improved the plasticity of these crushed stone chips by a simple method, and improved it so that it can be used as a civil engineering material such as a sub-base course material for roads etc. or a material for building land. Various studies were conducted on the addition of lime, cement, etc. As a result, the properties of the fine particles such as clay contained in the crushed stone waste were changed by kneading the cement-based mixture with properly ground water and curing it naturally for more than 12 hours. We succeeded in completely improving the plasticity of the material and converting it into a material with greater supporting capacity.

The present invention aims to utilize crushed stone waste with high consistency by improving its properties, thereby contributing to the utilization of resources.

The gist of the present invention to achieve the above object is as follows: 100 parts by weight of anhydrous base of crushed stone waste containing fine particles and high consistency, 2 to 4 parts by weight of a binder mainly composed of Portland cement, and 10 to 10 parts by weight of water. 15 parts by weight of crushed stone chips, kneaded, and naturally cured in the open air for 12 hours or more.

Crushed rock waste containing fine particles such as clay usually has a water content of about 8% to 10%, except during or after rain, and those that have been left to accumulate naturally for several weeks usually have a water content of about this level. becomes. In the present invention, such crushed stone waste is first sieved to a certain particle size, for example, 20 mm or less, and the moisture content is measured, and then 2 to 4 weight parts of a binder whose main component is cement is added to 100 parts by weight of the anhydrous base of this crushed stone waste. The water content is adjusted to a total of 10 to 15 parts by weight, and the mixture is quickly kneaded using a kneader.

A pinter containing portland cement as a main component may be made of ordinary portland cement alone, or may be made by adding lime or friance q, or a dispersant or the like may be added.

The binder of the present invention coarsens fine particles of several gm to several tens of meters in crushed stone waste to several + gm to several hundred μm, thereby significantly reducing the number of fine particles that cause plasticity. In this respect, the present invention is fundamentally different from "soil cement," which produces concrete with a poor mix to form road bases and roadbeds. "Soil cement" is made by adding about 2 to 6% cement and appropriate water depending on the material on-site or to crushed stone with a nearly continuous particle size whose particle size distribution has been properly adjusted so that the compacted coal is high. It is a kneaded material that is compacted and compacted immediately after kneading to integrate it into roadbeds and roadbeds such as roads. In contrast, the present invention coarsens only the fine powder of crushed stone chips with large consistency, and within 12 hours after kneading.
Preferably, the material is naturally cured in the open air for 24 to 48 hours, and the material is not solidified into a large lump by a pinter. That is, even if the material of the present invention is expanded and consolidated after natural curing, the pinter has no ability to agglomerate the entire material, and the material only loses its plasticity.

If the amount of the binder added is less than 2 parts by weight based on 100 parts by weight of the anhydrous crushed stone waste, the plasticizing property of the crushed stone waste cannot be sufficiently improved. On the other hand, if more than 4 parts by weight is added, the material will partially solidify and form large lumps during the natural curing period in the open air, which is undesirable, and the price will rise, making it uneconomical.

The moisture content is 10 to 1 per 100 layers of crushed stone layer anhydrous base.
It will be a 5-layer turtle part. Usually crushed stone waste is 8%~l as shown in -.
About 0% moisture (anhydrous pace io.

Since it contains about 9 to 11 parts of water (based on the crushed stone waste in the heavy part), it is often not necessary to add water during kneading, but it is better to add 1 to 2 parts by weight of water for more uniform kneading. This is often preferred for this reason. If the water content is less than 10 parts by weight based on the crushed stone layer of anhydrous heath, the effect of coarsening the fine grains of the binder will not be sufficient, and if it exceeds 15 parts by weight, the hydration of the binder will progress and the material will become agglomerated. Undesirable.

The present invention makes it possible to improve the plasticizing properties of the crushed stone layer, which had to be discarded in the past, and it has the same performance as crusher thin.1- It is now possible to use wood materials, for example, as the sub-base course material for roads. Now you can.

Next, the effects of the present invention will be explained in more detail with reference to Examples.

EXAMPLE A crushed stone layer 1 separated from rough stone at a crushed stone factory was improved in plasticity according to the process shown in FIG.

The crushed stone layer was sieved through a sieve 2 with a mesh size of 20 mm, and the undersize 3 (particle size 20 to 0 mm) was used as a raw material. This raw material 3
Table 1 shows the water content ratio, particle size, liquid limit, plastic limit, plastic index, etc. This raw material has a liquid limit of 31.0%, a plasticity limit of 21.0%, a plasticity index of 10.0, and a CBR of 29.8%, making it difficult to use as a civil engineering material.

This raw material bar stone waste 1001-ton is quantitatively discharged from the hopper 4 using a quantitative discharge feeder 5 at a constant discharge rate, and a total amount of 2 tons of ordinary Portolan 1ζ cement is poured into this crushed stone layer from a cement silo 6 by a quantitative feeding device 7. was uniformly supplied as a binder, and on the other hand, a total amount of 0.5 tons of water was uniformly added by means of a pump 8 via a control valve 9, and the mixture was kneaded using a paddle mixer 10 having a capacity of 200 tons/hour. Measurement of raw material moisture and control of throughput were carried out by an Oa control device 11 according to the system shown by broken lines in FIG.

The amount of binder mixed in and the water content in this example are 2 parts by weight of cement per 100 parts by weight of the raw material bar stone on an anhydrous basis.
．． 3 parts by weight, moisture content of raw materials 13.9 parts by weight, 0% water content,
The total moisture content was 6 M parts and 14.5 M parts. After kneading the above materials, conveyor 12 transported them to storage area 13
The materials were transported to a warehouse, piled up, and naturally cured for 24 hours. The average temperature at this time was 22°C.

Water content of plasticity modifier after 24 hours of natural curing treatment (11,
Particle size, liquid limit, plasticity limit, and plasticity index are also listed in Table 1.

As is clear from Table 1, by the method of the present invention, the crushed stone layer loses its plastic limit and liquid limit, and becomes NP (Non-Pl).
astic), and the plasticity of the raw material was completely improved.

In addition, the water content after plasticity improvement is 10% compared to the raw 4% anhydrous base.
Since it is in parts by weight, it is thought that 4.5 parts by weight were involved in the reaction of the binder.

The particle sizes of this raw material bar stone waste and the improved material are shown in a logarithm scale of 11 in Fig. 2. 20 is the raw material bar stone waste, 21 is the material after treatment *11
It is. From FIG. 2, it is clearly recognized that the particle size of fine particles in the clay, silt, and fine sand regions is becoming coarser.

In addition, the part of these samples with a particle size of 2 mm or less was sieved, an air-dried sample was taken, and the sample was soaked in 250% tap water.
Fig. 3 shows how the precipitate settled when it was put into a measuring ring together with mD, shaken for 1 minute, and then allowed to stand still.

(a) is the raw stone chips, (b) is the treated material. In (a), a fine particle layer of 21 mm was formed on a coarse particle height of 33 mm, but in the treated material, a fine particle layer of N4 m was formed on a coarse particle height of 39 mm. m
was produced, and it was clear that coarsening of the fine particles was achieved by the treatment of the present invention.

Therefore, these also prove that the present invention can improve the plasticity of the crushed stone layer.

In addition, as another effect of this plasticity improvement treatment method, CB
R has increased to more than 110H, making it a material with excellent performance as a road subgrade material, etc.

Table 1

[Brief explanation of the drawing]

Figure 1 is a process diagram of the treatment method of the present invention, Figure 2 is a graph showing the raw material crushed stone layer and the material particle size distribution after treatment of the present invention, and Figure 3 is a graph showing the material particle size distribution after the treatment of the present invention.
The figure is a side view of a measuring cylinder showing the results of a sedimentation test of the raw material crushed stone layer and the treated material of the present invention. ■...Crushed stone layer 2...Sieve 3...Undersize 4...Hopper 5...Quantitative discharge feeder 6...Cement silo 7...Quantitative supply device 8...Pump 9...・Control valve 10...
Paddle mixer 11...Control device 12...Conveyor 13...Storage area 20...Raw material crushed stone layer 2I...Junjin for processing material according to the present invention Ninokura Co., Ltd. Development agent Patent attorney Yoshio Kosugi 3rd (Q) (b)

Claims (1)

[Claims] l To 100 parts by weight of anhydrous base of a crushed stone layer containing fine particles and high consistency, 2 to 4 parts by weight of a binder mainly composed of Portland cement and 10 to 15 parts by weight of water were added and kneaded for 120 minutes. A method for improving the plasticity of a crushed stone layer, which is characterized by natural curing in the open air.