WO2019035782A1

WO2019035782A1 - A method of obtaining building materials by arranging/adjusting and/or improving the amount of strontium (sr) element in the structure of calcium sulphates

Info

Publication number: WO2019035782A1
Application number: PCT/TR2017/050388
Authority: WO
Inventors: Yonca İnkaya
Original assignee: Inkaya Yonca
Priority date: 2017-08-15
Filing date: 2017-08-15
Publication date: 2019-02-21

Abstract

The invention is related to a method of obtaining building materials by arranging/adjusting and/or improving the amount of Strontium (Sr) element and the amount of crystal water in the structures of natural calcium sulphate derivatives.

Description

A METHOD OF OBTAINING BUILDING MATERIALS BY

ARRANGING/ADJUSTING AND/OR IMPROVING THE AMOUNT OF STRONTIUM (SR) ELEMENT IN THE STRUCTURE OF CALCIUM

SULPHATES

Technical Field

Prior Art

Mineral aggregates or filler materials such as cements and limestone and/or calcite, marble powder, quarts or silicium sand are used in filler mixtures or building chemical products that are known as construction or building materials. Additionally, other mineral or artificial filler materials, organic or inorganic binders, rheology regulators and/or other additives are added to the mixtures. The contribution of mineral materials used as fillers or aggregates in these mixtures is limited with their mineral filler characteristics. For example, as these materials do not have any extra binding properties, and as the water absorption values of especially limestone group rocks are high, the water absorption or capillary water absorption values of the mixture is also increased.

As they do not have binding properties, it is mandatory to use higher amounts of cement and/or organic and/or inorganic based binders or other additives in the mixtures where said mineral materials are used. These binders and additives which are expensive not only increase the strength values of the mixture but also may increase the water impermeability capacities of said mixture. At the same time these mixture products that are obtained as mentioned above, also lose their environment-friendly characteristics. The reason for this is that the more the cement or organic or inorganic based binder or other chemical additives inside said mixtures that have been obtained by known inert aggregates/mineral fillers increases, the more they are indirectly harmful to the environment. Negative environmental effects are observed during the production of especially binders such as cement used in higher amounts in order to obtain higher durability and water impermeability values; besides this the durability or long life of buildings and the healthy living environments inside said buildings are also negatively affected; moreover the water vapour permeability coefficient mentioned in the quality standards and the related regulations that support heating economy is also negatively affected. Additionally, the mixtures obtained by using higher amounts of cement and/or binders lead to application difficulties in terms of the person carrying out the application during said application and problems such as expansion, shrinkage, cracking or contraction are faced. These problems, make it mandatory to add in high amounts, the rheology regulators, and other modified, improved organic and/or inorganic additives into the mixture. This in turn makes these mixtures to be less environmental and causes additional cost increases.

Various improvements have been applied to the technique in order to obtain the performance values anticipated by the market and to minimize such problems.

Natural or synthetic calcium sulphate derivatives are also used in building chemicals and filler mixtures. Moreover, due to the quality standardization in natural calcium sulphate derivatives and other problems, several improvements have been carried out and are still being carried out in relation to synthetic calcium sulphate production. These processes are quite expensive. The general view that is generally known or known in the prior art is that, the anhydrites and hemihydrate gypsums which are calcium sulphate derivatives that are used in product mixtures such as mortar, plasters, adhesives, fillers etc in building materials in general, have binding properties and that they provide high strength, however the most important problem of these materials is that they have late setting properties.

Indeed the developments carried out in order to produce such mixtures in the prior art have provided solutions to the late setting characteristics by adding additives that have setting accelerator properties such as potassium sulphate into the mixture in order to solve the late setting problem of the natural anhydrite and/or natural hemihydrates gypsum mineral which provides high strength.

Various solutions have been provided in the Chinese patent document numbered CN101367639 such as using setting regulating activation products and/or grinding the material to have a very fine material (less than 200 microns, 90 microns) or obtaining the material with small size distribution ranges or providing mechanical improvements using grinders, or applying methods such as calcinations and other similar methods.

In order to reduce the crystal water amount within the derivatives that can be named as hemihydrates gypsum and/or gypsum and/or natural anhydrites, solutions have been found for the insufficiency of durabilityand the late setting problem by applying dehydration techniques and various products have been thereby been obtained.

Besides these, improved techniques have also been provided by using natural or industrial derivatives of some other inorganic minerals. In the German patent document numbered DE102013200121 of the known state of the art, a water resistant binding mixture has been developed by adding other additives to the triple combination that shall be obtained from zeolite and/or metakaolin, anhydrite and cement. Anhydrite III and/or anhydrite II and/or mixtures thereof which are synthetic anhydrite derivatives that are produced by means of a dehydration technique in a chemical process have been used in this triple combination, wherein the average particle size of the anhydrite d50 has been preferred to be below 100 microns and moreover they have specified in claim 6, that the anhydrite II had an d50 average particle size between 5-30 microns. This is different from the method of obtaining the structural material of the invention due to the fact that the anhydrite II is synthetic anhydrite and the amount of crystal water is 0% by weight. Anhydrite II used in the art is synthetic anhydrite. Because, as it is already known, there are not enough anhydrite reserves in nature to provide mass production having a 0% crystal water in quantity. On the other hand, even if the anhydrite II mentioned here is natural anhydrite with 0% crystal water which is not subjected to the dehydration process, the industrial application area of the related technique is also very limited, since natural anhydrite reserves with 0% crystal water are not abundant in nature such that they cannot be mass produced. In the German patent document numbered DE102013200122 known in the state of the art, the mixture contains alpha calcium sulphate hemihydrate. In addition, a binder has been developed by forming a quadruple combination with the use of cement, calcium aluminate cement, zeolite and/or metakaolin. The method of the invention differs from this embodiment due to the fact that the anhydride used in the example document is synthetic anhydride and also an indispensable quadruple combination. In nature there are not enough anhydrite reserves having 0% crystal water in quantity such that the mass production can be carried out. On the other hand even if the anhydrite mentioned here, is natural anhydrite having 0% crystal water that has not been subjected to a dehydration process, as adequate amounts of anhydrite reserves having 0% crystal water to perform mass production is not present in nature, the industrial application field of the related technique is quite limited.

As a difference to the method subject to the invention zeolite and/or metakaolin is a must have for both documents mentioned above. Another important point that is different is that both techniques have provided solutions only for fast setting or binder requirements that are water resistant.

The United States patent document numbered US2011197789 of the known state of the art, describes the formation of a concrete surface hardening product by using strontium based compounds and other additives in order to harden concrete or other cement surfaces. The surface needs to be prepared and cured before the surface hardener is applied to a surface and the invention involves the improvement of a surface that needs repair or improvement by means of applying a surface hardener on a surface. Although strontium based compounds have been used in the document given as reference, the aim of the building material production method subject to the present invention is to find a solution to problems that may occur later on, while the building material products are being produced and to obtain resistant and high performance products beforehand that can show durability as long as possible, following application. As a result during application or following application, procedures that may necessitate additional costs such as repair or restoration or improvement shall be reduced. On the other hand the building chemical mixture aimed to improve, repair or restore according to the method subject to the invention or the surface hardening agent, may show differences due to the other raw materials, additives and amounts used. In the article that has been published in 2014 titled "Effect of the strontium aluminate and hemihydrate contents on the properties of a calciumsulphoaluminate based cement" the effect of the strontium aluminate and hemihydrate content to the characteristics of calcium sulphoaluminate based cement has been examined (Velazco, G., et al. "Effect of the strontiumaluminate and hemihydrates contents on the properties of a calcium sulphoaluminate based cement." MATERIALES DE CONSTRUCCIoN 64.315 (2014)). The cement paste has been prepared with calcium sulphate hemihydrate and strontium aluminate in the examination. As a result of the examination, it has been mentioned that cement that does not comprise cracks and which is highly strong , having strontium aluminate addition could be obtained. Moreover the tests that have been conducted have proved that the addition of SrAl₂0₄ has a positive effect on compressive strength. According to the results of the tests, the strength of the material increases when strontium aluminate and calcium sulphate hemihydrate amounts in the samples used are increased. However cement material is a hydraulic binding material that has been produced by means of cooking procedures, wherein said procedures which are extremely costly are carried out in high temperatures, said cement material which cannot be found in nature naturally, is produced by mixing it with natural or alternative raw materials. However the materials used in the method subject to the invention (calcium sulphate derivatives) can be abundantly found in nature. When cement and calcium sulphate derivatives are compared technically and structurally, gypsum rock or gypsum, hemihydrate gypsum, especially anhydrite are minerals of a salt. Cement however is a hydraulic binder that has been produced. Gypsum rock or gypsum, hemihydrate gypsum, especially anhydrite can be used as aggregates or the main material for a building material; whereas cement is an intermediate product used for producing concrete or mortar. It is a material that is used less in mass together with aggregates inside concrete. When examined structurally they are both different matrices. Cement comprises different minerals inside its structure (alite, belite, aluminate, ferriteetc), whereas anhydrite, hemihydrate gypsum and gypsum comprise natural calcium sulphate or aqueous forms of calcium sulphate crystals. The materials used in the method of subject to the invention, are different in terms of structure from cement, and their usage area is also different.

Apart from the examples we have given above, continuous developments were made in the technique as alternative solutions to the present problems and said developments are still being continued.

The reason for this is that, the main aim is to meet all characteristics which are expected from building materials such as visual, physical, chemical and mechanical characteristics. It is anticipated for such building materials meet retention, absorbtion water, and to have characteristics such as water requirement of the mixture, adhesion, capillary water resistance, strength, durability against pressure, water vapour permeability, heat and sound insulation, and its resistance against acids together with lower costs and higher performances and to be environment friendly. And besides all of these characteristics it is also expected for the materials to have less dust, chipping, shrinkage, cracking and drawing characteristics

Moreover the storage and delivery conditions until the materials reach the final consumer following the production and packaging of the materials must also be taken into consideration; therefore the shelf life of the materials need to be long.

As all of these characteristics and expectations are difficult to be carried out and as the methods and techniques to be applied are expensive, more cement and additives have been added in the past to the materials.

Therefore a need to develop a method in order to obtain better building materials by adjusting/arranging and/or improving the amount of strontium (Sr) and the crystal water amount inside the structure of natural calcium sulphate derivatives that comprises strontium (Sr) has risen.

Objections of the Invention

The aim of this invention is to provide a method that enables to obtain higher performance building materials that are environment friendly and that are cheaper.

Another aim of this invention is to provide a method which comprises the steps of adjusting/arranging and/or improving the crystal water amounts and strontium (Sr) element within the structure of a material.

Detailed Description of the Invention The invention is a method used to obtain building materials comprising the following steps; - Measuring the crystal water amounts by weight of the calcium sulphate (CaS0₄) derivatives (anhydrite, hemihydrate, gypsum) that is to be used in the mixture of the building material,

Adjusting the crystal water amount inside the calcium sulphate (CaS0₄) derivatives within the mixture to be between the range of 0,01 to 15% by weight,

- Measuring the strontium element amount by weight inside the structure of the mixture comprising calcium sulphate whose crystal water amount has been adjusted,

- Adjusting the amount of strontium element inside the mixture to be between 0,04% and 20% by weight.

The invention is a method that is used to obtain building materials, wherein the during the step of adjusting the crystal water amounts of the calcium sulphate (CaS0₄) derivatives inside the mixture to be between 0,01 to 15% by weight, calcium sulphate derivatives having crystal water amounts within its structure between 0% to 20,93% by weight are added to the mixture.

The invention is a method for obtaining building materials, wherein during the adjusting step of the strontium element amount inside the mixture to be between 0,04%) to 20%) by weight, calcium sulphate derivatives comprising different amounts of strontium from the weighed strontium element amount measured forthe mixture is added to the mixture.

The invention is a method for obtaining building materials, wherein during the adjusting step of the strontium element amount inside the mixture to be between 0,04%) to 20%) by weight, compounds that comprise strontium element such as strontium sulphate (SrS0₄), strontium carbonate (SrCO)₃ , strontium oxide (SrO), strontium sulphur (SrS) is added to the mixture.

In the method the usage of anhydrites and/or hemihydrate gypsum and/or gypsum that function as both fillers and as binders have been considerably benefited from. In fine size distribution ranges formed of micron sized particles, not only mixtures having the desired strength and setting criteria are obtained, but also mixtures having other performance criteria such as high water repellent, capillary water absorption together can be obtained and by using more coarse particles that may reach up to 25mm as being aggregates or mineral fillers together with other micron sized particles inside the mixture, not only strength and setting criteria are met but also several mixtures providing other performance criteria can be obtained.

The usage area of the calcium sulphate mineral which is classified as anhydrite and/or hemihydrate gypsum and/or gypsum in the raw has been limited as it cannot be found with the same structure or quality at anytime everywhere in nature, as it is not standardized even in the same region or even inside the same rock piece, and as the reserve derivative shows differences in terms of quality and character. The quality differences faced when the calcium sulphate derivatives are not subjected to a chemical process cause these derivatives to be used less frequently.

Especially because they are evaporate formations, the adjustment/arrangement and/or improvement of the crystal water amounts and the strontium (Sr) element that may be found in different amounts inside its structure has been given as a solution in this method.

The main reserves of calcium sulphate minerals are gypsum which is also known as gypsum rock and anhydrite which are formed naturally and which are found as evaporates in several regions in the world. These natural sources are obtained by means of mining methods. Apart from being obtained from natural sources, calcium sulphate mineral is also obtained as a by-product following several processes.

As a result two types of calcium sulphates depending on the obtaining and production techniques thereof are present: natural and synthetic. Calcium sulphate minerals are classified as follows, depending on the crystal water amounts they comprise in their structures:

Calcium sulphate dihydrate (gypsum, gypsum rock),

Calcium sulphate hemihydrate (hemihydrategypsum),

- Calcium sulphate anhydrite (anhydrite)

When this classification is examined in terms of their chemical compositions, they comprise the following;

20.93% crystal water by weight inside the pure calcium sulphate dihydrate structure,

- 6.21% crystal water by weight inside the calcium sulphate hemihydrate structure,

0% crystal water by weight inside the anhydrite calcium sulphate structure.

Synthetic calcium sulphates in relation to the crystal water amount are produced by being subjected to a chemical process comprising hydration or dehydration methods.

In the dehydration process, different products are obtained depending on the temperature degrees within the system and the process technique.

Natural or synthetic anhydrite is a calcium sulphate which does not comprise any crystal water in its structure and due to this reason, theoretically the crystal water amount of the anhydrite is accepted to be 0%. However, calcium sulphate mineral reserves having 0% crystal water amounts such that mass and continuous production being homogenous and having a standard quality is not present in nature. However, anhydrite gypsum reserves together with gypsum and hemihydrate gypsum which are comparatively closer or the closest to having 0% crystal water amount are present.

The situation in synthetic anhydrites that are produced by means of various chemical, physical and mechanical methods is different. If they can be produced as homogenous or standard anhydrites however mechanical and physical extra improvements are not carried out, these anhydrites absorb water as soon as they exit the heat treating process phase. Due to this reason, in addition to dehydration costs, mechanical and physical improvement costs are also inevitable, and as a result anhydrite II is also produced according to this method.

In this method, calcium sulphate derivatives that are used in high amounts by weight are not products of a chemical process which have been obtained by the application of dehydration methods.

Again in the method, the calcium sulphate derivatives that are used in high amounts by weight, are not calcium sulphate derivatives either, which are named as synthetic gypsum, synthetic hemihydrate gypsum or synthetic anhydrite that are produced as by-products in order to utilize industrial waste, using methods such as de-sulphurization methods.

The calcium sulphate derivatives that have been defined in the method, comprise all natural calcium sulphate structures that are obtained from nature using known mining methods, comprising crystal water in their structures between the range of 0.00% to 20,93% by weight.

The most important reason for this is that it is a solution to the problem of not being able to find an abundant amount of calcium sulphate minerals having 0% or a small percentage of crystal water in their structures in the reserves everytime, where mining is continued. Mixtures comprising different and alternative solutions for mixtures having low performance values which are acceptable can be obtained by using hemihydrate gypsum and/or gypsum having higher crystal water content and by adjusting/arranging, improving the strontium (Sr) element and by changing the amounts and types of the other binders, inorganic and/or organic aggregates and/or other additives.

Sixty two different strontium compounds (minerals) are found in nature. The most commonly used minerals are celestite(SrS04) which is a sulphate mineral and strontianite(SrC03) which is a carbonate mineral. Celestite and strontianite minerals are generally found in sedimentary stacks and rarely in magmatic rocks.

In sedimentary sulphates, the element of strontium is found in different amounts. Aslo in calcium sulphate which is a sedimentary sulphate, the strontium element can be found.

In the method it has been determined that the amount of strontium in the filler mixtures and building materials obtained with calcium sulphate derivatives positively effects the characteristics such as binding of the mixture, compressive strength, bending strength, binding, adhesion, sticking and cohesion of the small particles to each other inside the mixture physically and chemically, adhesion of the mixture to the area it is applied to, non-chipping and water absorption values. The mixtures and building materials that have been prepared by calcium sulphate samples having higher strontium content in their structure are mixtures and building materials which can bind faster and stronger, which have much higher bending strength and higher strength, in which the small particles contained therein can bind and adhere more to each other and which have high adherence, whose chipping problem has been solved and whose water absorption values are lower to due these characteristics.

This effect of the strontium element enhances the ability of calcium sulphate to work efficiently on its own by creating a binding effect only on water-based mixtures of filler aggregates derived from both calcium sulphate derivatives, without any binder, cement or other additives and introduces very different and positive results such as not only having increased strength but also being highly reactive with water, having binder, cement and other organic, inorganic, chemical and similar additives inside the mixtures which are prepared with water, binder, cement and other additives, successful results are obtained.lt has been determined by means of the studies carried out in this method that when strontium was added it increased at least by a few folds, the effects of binders, cement and other additives in the mixtures.

When binders, cement or other organic, inorganic, chemical etc additives are used as much as the amounts used in the mixture of other known building materials, the binder, cement and other additives that have been used are too much for the mixture as the strontium that has been added reacts efficiently with the binders, cement and other additives used, and the applicability, binding, setting abilities, viscosity, adherence and all rheological characteristics of the mixture is affected.

As a result the mixture that is used may not be applicable. As a result lower amounts of binders, cement and other additives should be added to the mixtures and this will be sufficient for these mixtures and thisresults in extremely high advantages and differences.

This effect of strontium is quite important. Because the calcium sulphate derivatives which can be abundantly found in the world, but which remain idle which are not utilized efficiently and fruitfully as their continuity and quality standardization cannot be provided in terms of their usage in building materials, can be efficiently used in high amounts in the production of building materials by adjusting/arranging and/or improving said calcium sulphate derivatives.

Moreover this means that calcium sulphates can not only be used in building materials but they can also be used as fillers and binders more efficiently and fruitfully in all applications and fields in which they can be used.

It is a pre-requisiteof the building material production method to control by arranging, adjusting or improving the amount of strontium comprising inside the calcium sulphate derivatives that shall be used in order to benefit from the positive effects of the strontium element in building materials and fillers that have been obtained using calcium sulphate derivatives. One of the important points here, is the amount of strontium content besides the crystal water amount inside the calcium sulphate structure that is used. The amount of crystal water inside the calcium sulphate derivatives can be found in different amounts even in the same reserve. The studies show that when the crystal water amount in the structure of calcium sulphate derivative minerals decreased, the amount of strontium could increase.

While the strength values of some moulds poured from the mixtures are high in the method of obtaining a building material, some other values are relatively low. Although the crystal water amount is taken into consideration, it has been determined from time to time that the strength and adhesion values of some samples that have low crystal water content were also low.

However with the increase of the strontium element amount within the calcium sulphate samples used, it has been noted that the plasticities of the wet mixtures prepared with these samples, the rheological characteristics, and the binding by being combined with other binders and additives inside the mixture were higher and their workable life were longer. At the same time it has been observed that the consistences/viscosities of the mixture were ideal, and the settings and the strength increases were faster. Furthermore after setting, it has been determined that the mixtures in which the Sr element is higher, have better characteristics, it has been especially observed that the bending strength values were higher. During the controls carried out after one day following surface application, it has been observed that any kind of chipping was not present in the mixture that was set, and that the particles inside the mixture that was set had completely adhered to each other and the application surface, and that the mixture had gained strength. The 7 day tests that have been carried out for early strength also confirm these findings. For example, some of the calcium sulphate mixtures that we have obtained using the same amount of binders, cement and other additive materials can set quickly by binding perfectly to both the classic concrete surface and the gas concrete surface. They can continue to provide these characteristics the next day. In contrast, it has been observed that although the mixtures we have obtained using the same amount of binders, cement and other additive agents in different calcium sulphate derivative samples did not cause any problems on the classic concrete surface, their binding and strength qualities in comparison to other samples were very low. On the other hand, several problems have been faced on gas concrete surfaces. The particles of the mixture are bound to each other weakly and as a result, after the mixture is dried, chipping occurs and relatively lower strength results have been obtained.

Moreover, it has been observed that the mixtures obtained from samples with higher performance values had a shinier view, whereas it has been observed that the mixtures with lower performance values had a mat view. The amount of strontium inside the calcium sulphate mineral also affects the shine of the material produced. This in turn provides different advantages on the surfaces they are applied to.

The crystal water content inside both mixture structures has been obtained by means of the anhydrite calcium sulphate mineral low in weight (0.220%, 0.218%, 0.217%) and 0.35%> by weight). In studies carried out with both mixtures mentioned above, good results have been obtained in comparison to mixtures made with high crystal water content and other aggregates. However as it has already been explained above, quality performance differences are present between both sample mixtures.

The strength differences in the mixtures that have been prepared with calcium sulphate samples that contain different amount of strontium inside their structure having the same or similar amounts of crystal water have been shown in Table 1 below. RESULTS OF THE MIXTURES MADE WITH ONLY WATER

FORMULATION (The amounts are by

Compressive weight)

Stregths

Water Amount

Calcium Crystal 28 365 (Water amount Calcium

Mixture sulphate Sr water day day /Total dry sulphate Cement

Number type (ppm) (250 °C) (MPa) (MPa) mixture amount) amount amount

1 1 1731 % 0,220 6,75 8,41 %20,00 100,00% %0.0

2 4 1527 % 0,218 4,1 4,560 %20,00 100,00% %0.0

3 4 1527 % 0,218 3,8 5,85 %18,50 100,00% %0.0

4 Y 515 % 0,217 2,57 2,62 %20,00 100,00% %0.0

Table 1 : shows the results of the mixtures made with only water and natural anhydrite calcium sulphate and the differences of the strengths according to the amount of strontium (Sr) present within the structure of anhydrite calcium sulphate.

In the examples given in Table 1, natural anhydrite calcium sulphate has been used which has not been ground, which has been crushed inside a crusher and a powder machine and which has been sieved through a 500 micron sieve.

As it can be seen in Table 1 the crystal water amount of the calcium sulphate anhydrite derivatives used, are too close to each other. However the 28 and 365 day strength values of the mixture made with a sample type having 1731 ppm strontium in its structure have been found to be 6,75MPa-8,41MPa which are the highest values. In mixture 4, the strength value of the mixture carried out with an anhydrite sample having 515 Sr element in its structure is the lowest value that has been obtained.

RESULTS OF THE MIXTU RES MADE WITH WATER AND CEMENT

365 days FORMULATION (The amounts are by

Compressive water weight)

Stregth saturated Water

Mixt Compressi amount(Wat

ure Crystal 28 365 ve er amount Calcium

Num Anhydr Water Sr day day Stregth(MP /Total dry sulphate Cement ber ite type (25CTC) (ppm) (M Pa) (M Pa) a) mixture amount amount amount)

5 1 0,220% 1731 17,7 22,9 16,28 20,00% 97,50% 2,5%

6 4 0,218% 1527 13,5 15 12,41 20,00% 97,50% 2,5%

7 1 0,220% 1731 19,1 24,15 21,26 20,00% 95,00% 5,0%

8 4 0,218% 1527 14,2 16,38 12,63 20,00% 95,00% 5,0%

21,1

9 1 0,220% 1731 8 26,25 20,20 25,00% 92,50% 7,5%

15,7

10 4

0,218% 1527 7 17,7 10,85 25,00% 92,50% 7,5%

29,6

11 1 0,220% 1731 8 38,5 29,15 20,00% 87,50% 12,5%

Table 2: Differences show the strength differences according to the strontium (Sr) element amount difference located inside the natural anhydrite calcium sulphate structure by the addition of cement to the mixtures and the strength affects of strontium (Sr) element inside the anhydrite in the mixtures containing cement. In the examples given in Table 2 natural anhydrite calcium sulphate has been used which has not been ground, which has been crushed inside a crusher and a powder machine and which has been sieved through a 500 micron sieve.

As it can be seen in the examples given in Table 2 higher compressive strengths have been obtained, in comparison to mixtures made with natural anhydrite having higher amounts of strontium (Sr).

On the other hand, as an additional explanation to the benefits in the usage fields, it can be seen in the examples in the tables that higher strength ratios in time (at the results of the 365 day Compressive Strength) has been obtained depending on the increased amount of strontium inside the anhydrite structure used in mixtures prepared with the same amount of water.

According to the information given above, it can be observed that as the Sr amount inside calcium sulphate increases both the 28 day and the 365 day strength also increases. This situation is valid for mixtures both comprising cement and not comprising cement. Moreover besides short term strength, the fact that the long term strength have increased (365 day strength), it has shown that the material has not lost its endurance during time, but has gained more resistance in time. It means that the in the areas which it shall be used, material will gain resistance against humidity or water if subjected to them. This also implies that in time, it shall continue to gain strength.

The Effect On Strengths And The Test Results Carried Out With Tests In Which SrS0₄ And Cement Is Added To The Mixtures

Due to the further increase in the reactivity feature of strontium (Sr) together with the increase of particle count per surface unit; in the examples given in Table 3, natural anhydrite calcium sulphate has been ground in a grinding mill and materials below 800 micron sieve sizes have been used.

Table 3

The examples given in Table 3 have been ground in a grinding mill and below 800 micron sieve sized natural anhydrite calcium sulphate has been used.

With the addition of SrS0₄ increase in strength has been observed in 7 days strength. With the addition of only SrS0₄ to the mixture numbered 14 in relation to the water amount used, a significant difference of 73,3% has been observed in the compressive strength of the mixture numbered 15. While 20% water is used in mixtures 12 and 13, the 16% water used in mixtures 14 and 15 is the ideal water rate used according to slump flow tests.

As it can be seen when the mixtures comprising cement and those not comprising cement are examined, significant differences between them can be observed in terms of bending and compressive strength. Besides this, when we look at the bending strength and compressive strength between samples containing cement, we can observe that compressive strength increased because of the increase of the cement amount (mixture number 16 and 18). Moreover the addition of SrS0₄ has provided a positive effect on strengths (mixture number 16 and 17 and mixture number 19 and 20). The reaction of added SrS0₄ with the cement itself and the additives inside the cement, may explain the effect on resistance.

When mixtures 12 and 16 are compared with each other, it has been noted that the 7 day compressive strength has increased 215,28%) and that 28 day compressive strength has increased 127,28%) and the daily compressive strength has increased 88%o, with the addition of only 2,5% cement. The difference of the Sr element inside these calcium sulphate samples used in these samples is 40ppm. When the mixture numbered 4, having a 28 day compressive strength of 2,57MPa containing 515ppm Sr is taken into consideration, it is thought that the difference of only 40ppm Sr should not cause such a high strength difference.

When the mixtures which do not contain cement are examined, it has been determined that the addition of 2.5% cement caused significant increase in both 7 day and 28 day strengths. When the results of the 7 and 28 day compressive strengths of the mixtures that contined cement are examined, it has been noted that the strength values were close to each other. As the amount of cement rate increases and the compressive strength increases, although Sr continues to increase compressive strength, it's effect on compressive strength is somewhat reduced. However when we look at the bending strength values of the mixtures that contained cement into which SrS0₄ was added, higher values are reached in 28 day strengths in comparison to 7 day strengths. It has been noted that when the amount of Sr increased in the mixtures that contained cement, the bending strengths also increased. When mixtures numbered 16 and 20 are mixed, a 37,6% strength increase has been noted with the addition of 1,59% SrS0₄. When mixtures 16 and 18 were compared it was observed that the addition of 2,5% cement did not lead to such a number of increase.

As it is known in order to meet the expectations of the users such as the increase of adherence, the improvement of rheological characteristics in building chemical product mixtures, by adding other additives (cellulose, polymeric materials, perlite and other similar additive agents) leads generally to the reduction of strength values. Due to these reasons, cement at the amount of 25-30% of the total dry base by weight according to the aggregate type (limestone and/or calcite, marble powder, quartz or filler aggregates such as silicium sand) used and the change in formulations needs to be added. This amount may also need to be increased in order to achieve the desired characteristics. However as it has been mentioned and explained above, in mixtures prepared using Sr containing calcium sulphate derivatives the usage of cement amount is decreased. At the same time due to the reactive characteristic of Sr, the other additives can also be used in much lower amounts.

Besides the strength values of the mixtures that have been prepared, the building chemical additives have also been used in order to meet other expectations in the market in terms of rheological characteristics and application facilities and the effects thereof have been examined. In order to achieve this, mixtures have been prepared using building chemicals, Sr containing calcium sulphate and other known fillers (limestone and/or calcite, marble powder, quartz or silicium sand) and when the results were examined, it has been noted that the calcium sulphate mixtures showed superior strength. Moreover with the addition of Sr it has been noted that strengths and especially bending strength continued to increase. Mixtures that can be obtained with the method of obtaining building chemicals can be obtained without using any kind of dehydration method, without changing the natural structure, and by adjusting/arranging or improving the crystal water amount and strontium (Sr) element amount within the calcium sulphate mineral, following the obtaining of the desired particle size distribution and by adding other binding, inorganic or organic aggregates and other additive agents, and finally by mixing in, any kind of building chemical mixer known and used in the prior art. The mixtures can both be produced as liquid, paste or powder as ready mixed and also the amount of water or liquid that needs to be added prior to application can be added at the application site. The mixtures can also be produced as dual component products.

Calcium sulphate mineral, that has been used as a mineral filler, aggregate or binder, is obtained by known mining methods. The important point here is that, "both the crystal water amount and the strontium element amouny within the structure of the mineral" is adjusted/arranged and improved.

As an easy method, always drilling should be conducted at the area where blasting is to take place before blasting designs and the crystal water and strontium element amounts of the calcium sulphate mineral inside the reserve that is not too deep, must be determined at frequent and regular intervals. The amount of Sr element can be determined as ppm or percentage value.

In evaporate formations Sr element can show regional differences frequently and small and large blasting must be carried out in order to provide standardization in accordance with the determination of Sr amounts. Again, according to determinations of Sr amounts, the blasting holes can be deep or shallow, narrow or wide. The same method applies for the crystal water amount. As a result, separation and quality standardization procedure can be started while the material is at its reserve.

The calcium sulphate mineral, which contain Sr element and crystal water amounts within their structure that has been obtained following blasting can be stored in groups while they are in rock formation according to Sr element and crystal water amounts within their structures. As a result the materials having lower Sr element and those having higher Sr elements, is prevented from being mixed with each other and from gypsum being mixed with hemihydrates and anhydrite gypsum/anhydrites randomly which makes it harder to achieve quality standards.

Gypsum together with anhydrite, anhydrite/anhydric and hemihydrate calcium sulphates can also be used within the method of obtaining building materials. For this reason, the calcium sulphate derivatives defined in the method encompasses all natural calcium sulphate derivatives that comprise crystal water in their structures between 0,00% to 20,93% by weight.

The stocks whose quality has been determined beforehand and which have been classified shall be mixed with each other according to the required and determined amounts of the mixture formulations, and therefore the crystal water and Sr element contents are adjusted/arranged and said materials are mixed and are ground in a grinding machine or a powder machine and are sieved and separated in order to achieve the particle distribution sizes suitable to the formulations. As a result the material is classified at the desired particle size distribution ranges as standard quality micron or granule form. The most ideal products are obtained from mixtures having high Sr element but low crystal water content.

In the case that the Sr element amount in natural reserves or stocks are insufficient, improvement can be made by adding compounds comprising Sr element to the mixture system or during grinding. The compounds comprising Sr element must be preferred according to their performances in the mixture, their costs and availabilities. The crystal water content in the structure of the calcium sulphate raw material to be used in the method must be at most 15%, preferably lower than 6,21%, more preferably 2%, even more preferably 1%, most preferably between the range of 0,01% to 0,50% by weight.

The total of the Sr element amounts to be added later on to the system and the Sr element amount in the structure of the calcium sulphate raw material within the mixtures in the method is between 400 to 200 000 ppm by weight of the calcium sulphate amount that is used in the mixtures.

Sr element is added, between 0,04% to 20% by weight of the total materials into the mixture that has been prepared by mixing the calcium sulphate raw material with the limestone, calcite, marble powder, and inorganic filler agents such as silicium sand.

Any kind of cement and/or a combination thereof, basaltic pumice and/or white pumice to provide strength and heat insulation to the mixture, perlite which increases heat insulation and provides volume and makes the mixture lighter, fiberglass and/or stone wool that increases strength to heat and noise permeability; setting or strength/resistance adjusterswhich increase the physical and saturation characteristics of the mixture, plasticizers/fluidifiers, water repellents, antifoaming agents, anti cracking agent, thickeners, water retainer, drying retardant, adhesive, sagging preventer, foaming agents and/or expansion agents, white and coloured pigments, microspheres antioxidants, types of fiber, bentonite, types of lime, inorganic and/or organic fillers or mixtures thereof, inorganic and/or organic resins or mixtures thereof, inorganic and/or organic binders or mixtures thereof, types of cellulose and polymers, activators, plasticizers/fluidifiers, air entrainers, heat insulation, water insulation and water permeability providing mixtures/admixtures or additive agents can be added to the dry base mixtures obtained by means of the method subject to the invention.

Some mixture examples prepared according to the technique described above and some performance values, have been described below. RESULTS OB^r ΓΑΙΝΕϋ BY ADDING SrS04 TO THE MIXTURES PREP ARED WITH ANHYDR] ΓΤΕ CALCIUM SULPHATE, CEM ENT AND OTHER AD DITIVES

Mixture Bending

Crystal Added Compressive Strength Number- Sr Strength water SrS04

Calcium (ppm) 28 Day

amount Amounts 7 Day MPa 28 Day MPa Sulphate Type MPa

21- Yl 0,217% 871 - 4,3541 9,7955 1,0015

22- Yl 0,217% 871 0,6153% 4, 153 9, 1647 1, 1681

23- Yl 0,217% 871 0,8204% 4,481 10,083 1,4031

Table 4

As it can be seen in Table 4, it has been noted that the strength values of mixture 21 prepared with calcium sulphate containing 871 ppm Sr, cement and other additive agents as a plaster mortar, was higher than standard values.

However following the application, especially on gas concrete of this plaster mortar, problems such as chipping (small particles cannot bind physically or chemically) and low binding and adhesion were faced. Mixture 22 prepared by adding 0,62% SrS0₄overcame all of these problems. The problems of chipping, low binding and adhesion have been solved in mixture 23 that has been prepared by adding 0,82% SrS0₄ and much better results in terms of rheology was obtained. Together with the addition of 0,62% SrS0₄, 17% increase and with the addition of 0,82 SrS0₄, 40% increase in bending strength have been obtained.

The mixture formulation of the sample given in Table 4 has been provided in Table 5. As it can be understood from Table 5, cement has been used at a low amount of 18% by weight and binders and additive agents such as polymers, cellulose and calcium hydroxide have also been used in low amounts. This formulation easily meets the EN 998 standard. If cheaper mixtures are desired, different mixtures can be prepared using lower amounts of cement or additives.

THE ADDITIVES USED AND DETERMI NED

ANHYDRITE Yl (800 ⁴m) CRITERIA

CRYSTAL WATER (250 °C) 0,217%

WATER ABSORPTION OF ANYHYDRITE BY

0,18%

WEIGHT 105°C ANHYDRITE Yl Sr (PPM) 871

Anhydrite (-800 micron ground in a mill)(KG) 76,9600%

CEMENT (KG) 18,000%

Ca(OH)₂ (KG) 2,500%

Vinyl Asetate Ethylene Copolymer (KG) 0,500%

Hydroxypropyl Methyl Cellulose (KG) 0,200%

Polyproylene Fiber (KG) 0,040%

Accelerator (KG) 0,800%

PERLITE (1.5 mm) 1%

WATER RATE OF THE MIXTURE 23%

COMPRESSIVE STRENGTH (N/mm²) 9,7955

BENDING STRENGTH (N/mm²) 1,0015

CAPILLARY WATER ABSORPTION (kg/m².

min0,5) 0,18

HEAT CONDUCTIVITY w/m.K (Ρ=%50^) 0,37

DESNITY OF DRY BULK (gr/cm³) 1272

Table 5

The formulation given in Table 5, is a formula of a mixture without the addition of SrS0₄ (Mixture 21). In mixtures 22 and 23, SrS0₄ has been added to the mixture and that much added amount has been reduced from the natural anhydrite calcium sulphate amount in the formulation of mixture 21.

The scan electron microscope images and the structures formed of some materials have been given below as an example to the formulations described in the technique.

CRITERIA USED AND

Dl D3 D4

DETERMINED

SR ELEMENT AMOUNT IN THE

1148 1148 1148 CALCIUM STRUCTURE (PPM)

RAW MATERIAL (-850

100,00% 97,50% 95,00% micron)(KG)

CEMENT Ceml (KG) 0,00% 2,50% 5,00%

Water amount rate of the

16% 16,00% 16,00% mixture

Dl: Natural calcium sulphate sample mixed only with water and poured into a mould

Sample prepared by adding 2.5% cement to 97.5%

D3: anhydrite

Sample prepared by adding 5% cement to 95%

D4: anhydrite

Table 6: Formulations of Dl, D3 and D4 samples used in SEM (scan electron microscope) images.

The type of calcium sulphate used in Dl, D3 and D4 samples is Y6-1. Natural anhydrite calcium sulphate is ground in a powder machine and is turned into powder form, the material is then sieved through a 850 micron sieve and has been used in the formulations of Dl, D3 and D4 samples. The samples have been poured into a mould according to EN 998 standards and have let to set for 28 days.

The formulations Dl, D3 and D4 have been prepared in order to prove the structural differences of the mixtures that have been obtained using calcium sulphates containing a certain amount of Sr with cement or without cement, after they have been set.

Table 7: Shows the Energy Distribution Spectroscopy (EDS) analysis values of the scan electron microscope (SEM) images belonging to the Dl sample.

When the Dl sample whose SEM image given in Figure 1 is examined, anhydrite mineral can be observed. When we look at the EDS analysis it is supported that the sample is an anhydrite mineral. Moreover the presence of the Sr element in the sample is also verified. In general view, Sr has been determined which is thought to take place around the calcium sulphate crystals inside the sample. In figure 2, the calcium sulphate crystal can be seen clearly in the SEM view belonging to D3. It should be especially pointed out that Sr element inside the calcium sulphate crystal could not be determined.

Table 8: Shows the Energy Distribution Spectroscopy (EDS) analysis values of the scan electron microscope (SEM) images belonging to the D3 sample shown in

Figure 2.

In the EDS analysis of D3 shown in Figure 3, Sr that is specifically thought to be located more around the calcium sulphate crystals has been determined.

Table 9: Shows the Energy Distribution Spectroscopy (EDS) analysis values of the scan electron microscope (SEM) images belonging to the D3 sample shown in

Figure 3.

In Figure 4, EDS analysis of D4 is given.

0 κ 48.19 68.13 203.35

SiK 1.07 0.86 31.35

SrL 0.2 0.05 2.98

S K 17.28 12.19 490.58

CaK 33.26 18.77 584.21

Table 10: Shows the Energy Distribution Spectroscopy (EDS) analysis values of the scan electron microscope (SEM) images belonging to the D4 sample shown in

Figure 4.

When the images of the D3 and D4 samples are examined, gel formations can be observed together with anhydrite particles. This gel formation shows that anhydrite and cement reactions have taken place. Moreover when EDS analysis is carried out on the gel section by zooming it has been observed that Sr element was present. This in turn shows that Sr element reacts as a surface adhering material and aids in the formation of an interface and it increases strengths and the development of other characteristics.

Table 11 : Formulations of the Yl and Yl# used in scaning electron microscope images The strength values in the applications of Yl mixtures into which Sr was not added were noted to be lower and following the completion of drying of the sample applied, chipping was observed. In the Yl# sample of which the Sr amount was increased, following application, drying was checked and although complete drying did not occur in 24 hours, chipping was still not observed. After full drying occurred, chipping was still not observed. As it can be seen here, Potassium Sulphate which is a setting adjuster has been observed in also very low amounts together with cement and other additives.

In Figure 5, the images of the Scanning Electron microscope Yl has been given. In Figure 6, the images of the Scanning Electron microscope Yl has been given. In Figure 7, the images of the Scanning Electron microscope Yl# has been given. In Figure 8, the images of the Scanning Electron microscope Yl# has been given. In Figure 9, the images of the Scanning Electron microscope Yl# has been given.

Table 12: Values of the Scanning Electron Microscope Yl# shown in Figure 9.

In Figure 10, the images of the Scanning Electron microscope Yl# has been given.

S K 25.65 21.32 3902.45

CaK 44.28 29.45 2802.38

Table 13 : Values of the Scanning Electron Microscope Yl# shown in Figure 10.

In Figure 11, the images of the Scanning Electron microscope Yl# has been given.

Table 14: Values of the Scanning Electron Microscope Yl# shown in Figure 11 In Figure 12, the images of the Scanning Electron microscope Yl# has been given.

Table 15: Values of the Scanning Electron Microscope Yl# shown in Figure 12

In Figure 13, the images of the Scanning Electron microscope Yl# has been given.

Table 16: Values of the Scanning Electron Microscope Yl# shown in Figure 13 In Figure 14, the images of the Scanning Electron microscope Yl# has been given.

Table 17: Values of the Scanning Electron Microscope Yl# shown in Figure 14

In Figure 15, the images of the Scanning Electron microscope Yl# has been given.

Table 18: Values of the Scanning Electron Microscope Yl# shown in Figure 15

When the SEM images of Yl and Yl# samples are examined, the presence of anhydrite minerals were observed. Moreover,it has been determined that the anhydrite crystals found in the Yl# sample were surrounded with fine crystal splinters. It can be seen that the strength features and physical characteristics of the anhydrite surrounded with these crystals that are ettringite and Sr are improved.

As a result Calcium sulphate used in the method contains Sr element. Calcium sulphates containing Sr element in their structures have been used by adjusting/arranging, improving the amount of Sr element. Thus, it has been determined that the mixtures showed positive changes in their properties such as strength after application, water absorption, adhesion and retention.

The samples of building materials and filler mixtures prepared with calcium sulphate containing higher amounts of Sr have better retention , better adhesion, water absorption and strength results in comparison to samples prepared with calcium sulphate containing lower amounts of Sr. SrS04 was added to the system in order to increase the amount of Sr and it was seen that the positive effects of the increase of the Sr amount on the material properties continued.

Improvements in calcium sulphate have been achieved by means of Sr, by adjusting/arranging the Sr element inside the natural calcium sulphate or improving by adding the Sr element to the natural calcium sulphate.

It has been explained in this invention that besides being able to use Sr element with calcium sulphate on its own, it can be used with different building materials and fillers and mixtures of calcium sulphate there-with. The increase in the cement amount naturally has a positive effect on the strength properties. However strength can be increased by keeping the cement amount at a constant value, but by increasing the Sr element amount.

The Sr element has a positive improving effect on the properties of building materials and filler agents even if it is not dependent on the matrix or regardless of its particle size.

Moreover even though known materials are durable for maximum 2- 6 months without deterioration depending on the climate and environmental conditions, the materials obtained according to the method described herein, can last for more than 1 year without agglomerationand deterioration and any kind of application problems have not been observed. This condition on its own provides significant benefits and differences and the damages to the product that may occur during storage and delivery of the products obtained using this technique are prevented and the shelf life of the product is prolonged.

Although the performance expectations depending on the application area, and the criteria relating to quality-cost of the calcium sulphate reserves in terms of Sr may show differences, in order to obtain better strength results, first of all the primary preference shall be to adjust/arrange the Sr content of the natural calcium sulphates. It has been observed that the mixtures prepared with calcium sulphates containing higher amounts of Sr elements in their structure provided better results in comparison to adding SrS0₄ to their structure.

In light of all of the results obtained; the below mentioned determinations have been reached in relation to the Sr amounts inside calcium sulphate in terms of both adhesion, chipping (small particles cannot bind physically or chemically), binding, radiance and strengths:

The best economic results have been obtained with calcium sulphates containing 1000-2000 ppm Sr. In order to obtain extra high performance products, higher amounts of Sr should be used and the amounts of other binders, cement and additives must be adjusted.

Good results have been obtained using calcium sulphate samples comprising more than 1100, from 1000 to 1100 and from 900 to 1000 ppm Sr respectively.

The tests carried out have shown that the calcium sulphate samples comprising less than 900ppm Sr may need to have an additional amount of Sr added, or may need to be mixed with calcium sulphates having higher Sr content and the Sr content therefore needs to be adjusted/arranged or improved. Indeedmixtures 21, 22 and 23 are mixtures prepared with calcium sulphate types comprising 871 ppm Sr and mixture 21 has shown performance problems on gas concrete surfaces. The problems were overcome after the product was improved.

When the properties of the mixtures prepared using calcium sulphate lower than 500 microns and water, it has been observed that the 28 day and 365 day strength values increased when the Sr element content was increased.

Increase in the strength values have been observed by adding 2,5% cement into the calcium sulphate sample that is below 500 microns. Additionally the increase in the Sr element amount, also leads to the extra strength of the sample. These results have been summarized in the tables given above. When the cement amount inside the calcium sulphate mixture downsized to be below 500 micron is increased to 7,5%, it has been observed that the strength value is increased. By increasing the Sr element inside the mixture, it has been observed that the strengths also increased.

It has also been observed that the increase in Sr also increased strengths in water and calcium sulphate mixtures that were below 800 microns.

Addition of cement into the same calcium sulphate also increased strengths. However the addition of Sr increased strengths at a higher value.

As the size distribution ranges of the calcium sulphate used gets narrower, and/or when the fineness values increased, the efficiency of the Sr in the structure also increases. Moreover it has been observed that it was more efficient to use Sr element by adding it into the grinding mill with calcium sulphate or other aggregates or with calcium sulphate raw material prepared in the grinding mill.

The crystal water amounts in the calcium sulphate mineral also need to be taken into consideration at all times in connection with the performance expectations of the area onto which the material (product) is to be applied. The invention cannot be limited to the examples given above and it should be understood to be described fully in the claims given below.

Claims

1. The invention is a method for obtaining building materials characterized in that it comprises the steps of;

- Measuring the amount of crystal water by weight of calcium sulphate (CaS0₄) derivatives (anhydrite, hemihydrate gypsum, gypsum) that are to be used in the mixture of the building material;

adjusting the amount of crystal water of the calcium sulphate derivatives (CaS0₄) inside the mixture to be between 0,01% to 15% by weight;

measuring the strontium element by weight, inside the structure of the mixture comprising calcium sulphate whose crystal water amount has been adjusted;

adjusting the strontium element amount inside the mixture to be between 0,04% to 20% by weight.

2. A method of obtaining building materials according to claim 1, characterized in that during the step of adjusting the crystal water amount of the calcium sulphate derivatives (CaS0₄) within the mixture to be between 0,01% to 15% by weight, calcium sulphate derivatives having a crystal water amount between 0% to 20,93% in their structure is added to the mixture.

3. A method of obtaining building materials according to claim 1, characterized in that during step of adjusting the strontium element amount inside the mixture to be between 0,04% to 20% by weight, calcium sulphate derivatives comprising different amounts of strontium from the amount of the strontium element measured is added.

4. A method of obtaining building materials according to claim 1, characterized in that during step of adjusting the strontium element amount inside the mixture to be between 0,04% to 20% by weight, compounds comprising the strontium element such as strontium sulphate, strontium carbonate, strontium oxide, strontium sulphur is added to the mixture. A method of obtaining building materials according to claim 1, characterized in that the obtained product comprises one or more agents such as cement, calcite, marble powder, limestone powder, silicium sand, basaltic pumice, white pumice, perlite, fiberglass or stone wool, setting adjuster, water repellent, antifoaming agent, anti cracking agent, thickener, water retainer, drying retardant, adhesive, sagging preventer, foaming agents and/or expansion agents, white and coloured pigments, types of fiber, bentonite, types of lime, other mineral fillers and binders, activators, fluidifiers/plasticizers, air entrainers, additives providing heat isolation, sound isolation and water impermeability, strength adjusters, microspheres , antioxidants, inorganic and/or organic fillers or mixtures thereof, inorganic and/or organic resins or mixtures thereof; inorganic and/or organic binders or mixtures thereof; varieties of cellulose, polymers or one or more additives agents comprising these.