Method for producing agglomerates from metal mine tailings

Abstract

The present application relates to the field of technologies aimed at reusing waste generated by the mining industry. In particular, the invention relates to a method for producing agglomerates from tailings originating from metal mining and an agglomerate for use as a replacement for aggregates.

Description

[0001] DESCRIPTIVE MEMORANDUM

[0002] FIELD OF TECHNOLOGY

[0003]

[0001] This application falls within the field of technologies for the reuse of waste generated by the mining industry. Specifically, it relates to a method for producing agglomerates from tailings originating from metallic mining and an agglomerate to be used as a replacement for aggregates.

[0004] BACKGROUND OF THE TECHNOLOGY

[0005]

[0002] The mining industry generates large volumes of waste, among which tailings are one of the most significant byproducts. These tailings contain very fine particles, which poses significant technical challenges in terms of storage and environmental management. Their disposal requires large-scale containment facilities and long-term management strategies, which entail high costs and potential risks. Therefore, there is a technical need to find alternative applications for this waste that reduce its environmental impact and facilitate its valorization.

[0006]

[0003] Likewise, there is a need for techniques that allow the stabilization of tailings, in order to reduce their environmental impact, for example, that caused by the leaching of potentially toxic elements into the soil, the contamination of surface and groundwater, and the air pollution resulting from their low particle size.

[0007]

[0004] Copper mining is a good example of the above, however, mining processes linked to the extraction of other metals generate similar problems.

[0008]

[0005] The construction industry, for its part, faces limitations related to the availability and sustainability of natural aggregates, such as gravel and sand. The intensive extraction of these materials generates negative impacts, such as ecosystem degradation, loss of biodiversity, and alteration of waterways. Therefore, it is desirable to have alternative products that allow for the total or partial replacement of natural aggregates, for example, in the preparation of concrete or other construction materials.

[0009]

[0006] In view of the above, the inventors made the decision to investigate and develop solutions that would allow the reuse of mining tailings as a replacement for natural aggregates, in order to mitigate the environmental impact of mining and promote a circular economy model through the revaluation of industrial waste.

[0010]

[0007] In this context, the production of agglomerates made from mining tailings emerged as a promising solution, as they could be useful in the manufacture of construction materials (for example, for the replacement of aggregates in the preparation of concrete), and also allow the physicochemical stabilization of the tailings, by encapsulating the potentially toxic components present in them and reducing their leaching.

[0011]

[0008] However, the inventors were able to note that the production of agglomerates that could be used, for example, as a replacement for aggregates, presented a number of challenges, linked to the development of a product with suitable physical and mechanical properties.

[0012]

[0009] In this regard, while technologies for using mining waste in construction materials have been described, better or alternative solutions are desirable. For example, patent CN110818350 describes a method for using copper tailings in concrete for roads, which includes cement, water, standard sand, and copper tailings. Another example is patent IN202331007737, which describes a sustainable concrete in which traditional cement and aggregates are partially or completely replaced by industrial byproducts, such as copper slag and steel slag. However, these documents do not refer to the use of agglomerates as an intermediate product, nor do they address the physicochemical stabilization of the tailings through agglomeration processes.

[0013]

[0010] Consequently, it is desirable to have new technologies and alternatives that allow tailings to be transformed into agglomerated products capable of totally or partially replacing aggregates in construction materials, such as concrete. Likewise, it is also desirable to have new tailings-based materials that allow for the replacement of aggregates in construction materials such as concrete.

[0014]

[0011] In view of the foregoing, the technology in this application proposes a method for producing agglomerates from tailings from metallic mining, useful as aggregates in construction materials that meet industry standards. Furthermore, this technology also includes new tailings-based materials that allow for the replacement of aggregates in construction materials such as concrete.

[0015] BRIEF DESCRIPTION OF THE TECHNOLOGY

[0016]

[0012] This application falls within the field of technologies for the reuse of waste generated by the mining industry. Specifically, it relates to a method for producing agglomerates from tailings originating from metallic mining. More specifically, the present invention comprises at least the following steps:

[0017] a. Sieve the tailings to obtain particles no larger than 2 mm; b. Add cement to the sieved tailings in a proportion of between 5 and 20% w / w, forming a mixture of solids;

[0018] c. Add the solids mixture to an agglomerating disc set at an angle of between 20 and 50°;

[0019] d. Rotate the agglomerating disc at a speed of between 10 and 28 rpm, until a homogeneous mixture is obtained;

[0020] e. Add water to the homogeneous mixture in a proportion of between 10 and 20% w / w;

[0021] and

[0022] f. Continue rotation until agglomerates of the desired size are obtained.

[0023]

[0013] The invention also comprises an agglomerate for use as a replacement for aggregates, comprising:

[0024] Tailings; and

[0025] Cement.

[0026] Where:

[0027] The cement is present in a proportion of between 5 and 20% m / m; and the resulting aggregates have a size of between 5 and 25 mm.

[0028]

[0014] The technology of the present invention presents a number of advantages, among which the following stand out.

[0029]

[0015] First, as identified by the inventors, one of the main challenges presented by mining tailings for use as a replacement for natural aggregates is their very fine particle size, substantially lower than that of the latter. Indeed, using very fine particle sizes hinders their direct use in construction materials, as it can negatively affect their workability, mechanical strength, and stability. In this regard, the method of the present invention allows the formation of agglomerates with a suitable size to replace natural aggregates.

[0030]

[0016] Secondly, the inventors noted that another challenge was achieving uniformity in size and shape in the agglomerates. Uniformity is particularly important for ensuring a homogeneous distribution within the mixture, which improves the workability, compaction, and mechanical strength of the final material, as well as facilitating compliance with the technical standards required for structural applications. In this respect, the present method also offers the advantage of producing agglomerates with uniform particle size and shape.

[0031]

[0017] Regarding the product consisting of agglomerates, it also has the characteristic of being able to serve as a replacement for aggregates in a range of construction materials, for example, in the formulation of concrete. However, other uses are also possible in construction materials, such as mortars or others.

[0032]

[0018] For reference, the Chilean technical standard establishes that aggregates used in mortars and concretes must comply with requirements related to, for example, particle size distribution, as well as physical properties such as adequate density. It should be noted that the parameters required by the standard may vary depending on the type of construction element to be manufactured, considering factors such as the dimensions of the component, the spacing between reinforcement bars, and the application conditions. Therefore, it is desirable to produce aggregates that exhibit these properties, as is the case with the technology of this application.

[0019] The technology of the present invention also has the advantage of allowing maximizing the quantity of aggregates within the required size range, which improves the efficiency of the process and the quality of the final product.

[0033]

[0020] The technology of this application enables the efficient reuse of mining tailings, potentially reducing the environmental footprint of the mining and construction industries by decreasing the need to extract new materials. In effect, the method of the present invention also contributes to the development of more sustainable construction practices by offering an alternative source of aggregates, thus helping to conserve natural resources commonly used in construction. Therefore, the present technology actively promotes a circular economy.

[0034]

[0021] Finally, the technology in this application not only provides an alternative for the construction industry, but also allows the transformation of fine particulate matter from tailings into larger agglomerates, offering environmental and operational advantages. This is because, being larger, the agglomerates are not easily dispersed by air. Furthermore, the formation of agglomerates reduces the leaching of potentially toxic elements into the soil, for example, during rainfall.

[0035] DESCRIPTION OF THE FIGURES

[0036]

[0022] The foregoing and other objects, features and advantages of the technology that is the subject of this patent will be evident from the detailed description of the invention and its preferred embodiments, as well as from the accompanying figures.

[0037]

[0023] Figure No. 1 corresponds to 5 samples of agglomerates obtained by the agglomeration process with a rotation speed of approximately 27.5 rpm (A and C), 16.5 rpm (B and D) and 21 rpm (E).

[0038]

[0024] Figure No. 2 corresponds to a graph showing the particle size distribution curves for agglomerates obtained by the agglomeration process with a rotation speed of approximately 16 rpm (blue curve), 21 rpm (orange curve) and 28 rpm (green curve). DETAILED DESCRIPTION OF THE TECHNOLOGY

[0039]

[0025] This application falls within the field of technologies for the reuse of waste generated by the mining industry. Specifically, it relates to a method for producing agglomerates from tailings originating from metallic mining and an agglomerate to be used as a replacement for aggregates.

[0040]

[0026] Different preferred embodiments of the invention will be detailed below. However, unless otherwise stated, the specific configurations, such as certain steps, raw materials, and other aspects of the invention, which constitute the respective preferred embodiments, are to be interpreted as illustrative only and not as limiting the scope of the present technology, unless otherwise stated.

[0041]

[0027] Specifically, the invention consists of a method for the production of agglomerates from tailings from metallic mining, comprising at least the following steps:

[0042] a. Sieve the tailings to obtain particles no larger than 2 mm; b. Add cement to the sieved tailings in a proportion of between 5 and 20% w / w, forming a mixture of solids;

[0043] c. Add the solids mixture to an agglomerating disc set at an angle of between 20 and 50°;

[0044] d. Rotate the agglomerating disc at a speed of between 10 and 28 rpm, until a homogeneous mixture is obtained;

[0045] e. Add water to the homogeneous mixture in a proportion of between 10 and 20% w / w;

[0046] and

[0047] f. Continue rotation until agglomerates of the desired size are obtained.

[0048]

[0028] The method of the present invention has a number of advantages, which derive from its particular configuration, as explained below.

[0049]

[0029] Preliminarily, the raw material used in the method consists of tailings from metallic mining, making it useful for transforming waste generated in copper, silver, zinc, or other leaching processes into agglomerates. In a preferred modality, the tailings come from copper leaching processes.

[0050]

[0030] Regarding the process itself, the stage of sieving the tailings to obtain particles no larger than 2 mm is relevant because it ensures a controlled and homogeneous distribution of the fine components in the resulting agglomerates. This particle size improves the efficiency of the agglomeration process, promotes the formation of stable agglomerates, and reduces the presence of coarse particles that could negatively affect the cohesion, shape, and strength of the final product. The inventors determined that the 2 mm limit is particularly suitable for agglomeration in a disc agglomerator, as it allows for the formation of small, uniform nuclei that grow through aeration (layer adhesion).Indeed, they noted that in those cases where tailings particles larger than 2 mm were used, excessively large nuclei were generated, resulting in agglomerates with a size greater than required, not useful to replace the aggregate in the formation of concrete.

[0051]

[0031] This operation can be carried out using various techniques, for example, using a No. 10 sieve according to ASTM standards. However, other alternatives could be employed by an expert in the field, depending on the available resources and the characteristics of the material.

[0052]

[0032] Although not indispensable, in one embodiment of the invention the cement is also sieved.

[0053]

[0033] The step of adding cement to the screened tailings at a ratio of between 5 and 20% w / w, forming a solids mixture, is relevant because it ensures a uniform distribution of the binder within the base material, which promotes the formation of stable agglomeration nuclei during the process. The inventors determined that this ratio constitutes an optimal range. Indeed, ratios below 5% generate agglomerates with low cohesion and mechanical strength, while ratios above 20% show a significant dependence on the type of tailings used.

[0054]

[0034] In a preferred embodiment of the invention, cement is added to the screened tailings at a proportion of approximately 10% w / w. The inventors determined that the advantage of this proportion is that it allows for a more uniform particle size distribution in the finished product, which promotes the formation of stable and homogeneous aggregates. Furthermore, this proportion offers economic and environmental benefits: on the one hand, it reduces cement consumption, resulting in lower input costs, and on the other hand, it maximizes the use of the tailings as the main component, contributing to the valorization of mining waste. For the purposes of this paragraph, “approximately” implies a difference of plus or minus 2%.

[0055]

[0035] In one embodiment of the invention, the cement added to the tailings can be selected from Portland cement, rapid-setting cement, or other types of cement.

[0056]

[0036] The next stage, which consists of adding the solids mixture to an agglomerating disc configured at an angle of between 20 and 50°, presents different implementation alternatives.

[0057]

[0037] The mixture can be added so that both solids (tailings and cement) are incorporated simultaneously into the agglomerating disc without prior mixing, or they can be pre-mixed. Therefore, the mixture can be added already prepared or formed directly inside the agglomerating disc by its rotational action.

[0058]

[0038] In a preferred method, the screening of the tailings and the cement are mixed for at least one minute in the same agglomerating disc before the water is added. This alternative has the advantage of facilitating the homogeneous distribution of the solids, reducing the time required to complete the process, compared to the procedure where the water is added immediately without the aforementioned prior mixing time.

[0059]

[0039] The angle setting of the agglomerating disc is particularly relevant. Selecting an angle between 20 and 50° offers the advantage of precise control over the residence time of the particles within the disc, which directly influences the efficiency of the agglomeration process. Furthermore, the inventors determined that this angle range favors the formation of optimal trajectories for particle collision and adhesion, promoting the generation of stable and homogeneous agglomeration nuclei. Finally, this angle facilitates a uniform distribution of the material on the disc surface, preventing accumulations that could affect the quality of the resulting agglomerates.

[0060]

[0040] In a preferred embodiment of the invention, the agglomerating disc is configured at an angle of approximately 45°. The inventors determined that the advantage of this angle is that it allows for a more uniform particle size distribution in the agglomerates resulting from the treated tailings. For the purposes of this paragraph, “approximately” means a difference of plus or minus 2%.

[0061]

[0041] In one embodiment of the invention, the agglomerating disc is made of stainless steel. However, other configurations would be possible.

[0062]

[0042] The stage of rotating the agglomerating disc at a speed of between 10 and 28 rpm, until a homogeneous mixture is obtained, is relevant because it allows control of the intensity of the interaction between the particles within the disc, favoring the progressive formation of agglomerates with a uniform structure and the desired size. The inventors determined that this speed range prevents both the disintegration of the formed nuclei and the formation of excessively large or irregular agglomerates. Furthermore, the rotation speed directly influences the efficiency of the process, ensuring adequate compaction and cohesion of the materials without compromising the stability of the system.

[0063]

[0043] In a preferred embodiment of the invention, the speed of the agglomerating disc is approximately 21 rpm. The inventors determined that the advantage of this speed is that it allows for a more uniform particle size distribution in the agglomerates resulting from the treated tailings. For the purposes of this paragraph, “approximately” means a difference of plus or minus 5%.

[0064]

[0044] The next step, which consists of adding water to the homogeneous mixture in a proportion of between 10 and 20% w / w, is relevant because it activates the agglomeration process by generating capillary forces between the solid particles, facilitating their adhesion and compaction. This step is carried out by adding water directly to the solid mixture on the agglomerating disc. In one embodiment, the water is added while the disc is in continuous rotation.

[0045] The inventors determined that a water content in the range of 10 to 20% w / w is suitable for promoting the formation of stable agglomerates without causing excessive saturation that would compromise the structure of the final product. This proportion also helps maintain the workability of the system and control the size and uniformity of the resulting agglomerates.

[0065]

[0046] In a preferred embodiment of the invention, water is added to the homogeneous mixture in a proportion of approximately 17% w / w. The inventors determined that the advantage of this proportion is that it allows for a more uniform particle size distribution in the agglomerates resulting from the treated tailings. For the purposes of this paragraph, “approximately” means a difference of plus or minus 2%.

[0066]

[0047] Finally, maintaining constant rotation of the disc until the desired size of agglomerates is achieved allows their structure to consolidate, ensuring a uniform distribution of water and binder throughout the mixture. This final agitation or rotation promotes the progressive compaction of the particles and the stabilization of the previously formed nuclei, resulting in more uniform agglomerates with greater mechanical strength and improved internal cohesion. Furthermore, this stage helps reduce the presence of loose particles, thus optimizing the quality of the final product.

[0067]

[0048] In one embodiment of the invention, the rotation applied during the preceding steps can be constant in terms of its speed.

[0068]

[0049] In one embodiment of the invention, the resulting agglomerates have a size between 5 and 25 mm. The inventors determined that this size range is comparable to that of coarse aggregates commonly used in the construction industry, such as gravel. This facilitates their incorporation into, for example, concrete and mortar mixes, allowing their use as a partial substitute for conventional aggregates.

[0069]

[0050] In another embodiment of the invention, the formed agglomerates are subjected to a drying process. The inventors determined that this step is relevant because it physically stabilizes the agglomerates, allowing them to reach their final mechanical strength and preventing disintegration during handling, transport, or storage. Furthermore, drying also reduces residual moisture, which improves the material's durability and enhances its performance as a substitute for conventional aggregates in construction applications.

[0070]

[0051] In a preferred embodiment, drying is carried out until the moisture content of the agglomerates is between 0.5 and 5%. The inventors determined that this moisture range ensures the mechanical strength of the material and minimizes its disintegration during use.

[0071]

[0052] In another preferred embodiment, drying is carried out at a temperature between 15 and 40°C. The inventors determined that this temperature range allows for progressive and controlled drying of the agglomerates, reducing the possibility of cracking or structural deformations that could compromise their mechanical integrity. Furthermore, these thermal conditions are compatible with drying processes at ambient temperatures ranging from 15 to 40°C or with moderate thermal assistance, thus improving the energy efficiency of the process.

[0072]

[0053] Drying can be done at room temperature or in a controlled environment.

[0073]

[0054] The invention also comprises an agglomerate for use as a replacement for aggregates, comprising:

[0074] Tailings; and

[0075] Cement.

[0076] Where:

[0077] The cement is present in a proportion of between 5 and 20% w / w; and

[0078] The resulting agglomerates have a size of between 5 and 25 mm.

[0079]

[0055] The agglomerates of the present invention exhibit high homogeneity in size and shape, which improves their distribution in concrete mixtures and favors properties such as workability, internal cohesion and mechanical resistance.

[0080]

[0056] In one embodiment of the invention, the moisture content of the agglomerates is between 0.5 and 5%. However, it should be noted that the moisture content may vary over time, especially during storage or marketing. Therefore, this range should not be interpreted as a technical limitation of the agglomerates. EXAMPLES

[0081]

[0057] The invention will be better understood by means of the following examples, which are merely illustrative and do not limit the scope of this application and the development of the invention. Various changes and modifications to the described embodiments would be obvious to those skilled in the art, and such changes may be made without departing from the spirit of the technology and the scope of the appended claims.

[0082] Example No. 1: Evaluation of rotation speed and tilt angle of agglomerated discs

[0083]

[0058] During the method development process and in the context of the tests carried out, the inventors noted that one of the main challenges of the method was the formation of agglomerates that met the required criteria for sphericity and particle size uniformity. In this regard, shape is relevant because a spherical geometry promotes the mobility and compaction of the agglomerates within concrete mixtures, improves load distribution, and reduces stress points, thus contributing to greater strength and durability of the final material. Size, meanwhile, is relevant because it ensures controlled particle size distribution, compatible with the technical standards for aggregates used in the construction industry, facilitating their incorporation into concrete mixtures and guaranteeing a homogeneous distribution within the material volume.

[0084]

[0059] In view of the above, the inventors evaluated a plurality of variables, to ensure a homogeneous production of agglomerates.

[0085]

[0060] A critical aspect of agglomerate production is verifying that the agglomerating disc is compatible with the tailings and cement mixture, in terms of its ability to rotate properly within the range of speeds of interest. If the addition of these components affects the disc's rotational speed, the method may require operational adjustments to ensure its efficiency.

[0086]

[0061] In view of the above, the inventors evaluated different combinations of rotation speed and tilt angle of the agglomerating disc, using copper mine tailings masses of 5, 10, and 15 kg. For each speed evaluated, the same power was applied, regardless of the mass of tailings used. The objective was to evaluate how these variables influenced the effective rotation speed of the disc. The results obtained are shown in Table 1.

[0087] Table No. 1: Rotation speed measurements at different inclination angles of the agglomerating disc, from different masses of tailings.

[0088]

[0089]

[0062] Based on the results obtained, the inventors concluded that neither the mass of tailings nor the selected tilt angles influenced the rotation speed, as it remained constant in all cases.

[0090]

[0063] They were also able to determine that maintaining an inclination angle of approximately 45° minimized material losses and ensured an efficient mixing process. Indeed, they observed that when the angle was less than 40°, the process efficiency decreased significantly, as the solid material did not agglomerate properly and loose particulate material remained on the disc. On the other hand, when the angle exceeded 45°, material was lost from the equipment, affecting the stability of the process. Consequently, the inventors selected the 45° angle as the preferred condition, as it allowed for better particle size distribution of the resulting agglomerates and more controlled operation of the system. Example No. 2: Evaluation of rotation speed as a function of agglomerate sphericity and homogeneity.

[0091]

[0064] Subsequently, the inventors conducted tests to identify the optimal rotation speed that would produce agglomerates with optimal sphericity and homogeneous particle size distribution. To this end, they evaluated three agitation speeds (approximately 16.5, 21, and 27.5 rpm), using samples of copper mine tailings that had been previously sieved to obtain a maximum particle size of 4.75 mm. They also maintained the previously selected tilt angle of approximately 45° and a fixed amount of water at a ratio of approximately 12% w / w.

[0092]

[0065] As can be seen in Figure 1, the agglomerates produced using a rotation speed of approximately 27.5 rpm (samples A and C) exhibited low homogeneity. In contrast, those produced at approximately 16.5 rpm (samples B and D) showed greater uniformity in their structure. Meanwhile, the agglomerates generated with an intermediate speed of approximately 21 rpm (sample E) presented superior sphericity and a more uniform particle size distribution compared to those obtained at the other speeds evaluated.

[0093]

[0066] These findings allowed the inventors to conclude that a rotation speed of approximately 21 rpm constituted the optimal condition for the formation of agglomerates that met the required criteria of sphericity and uniformity in particle size, while higher or lower speeds produced less consistent results.

[0094] Example No. 3: Water dosage evaluation.

[0095]

[0067] Once the optimal rotation speed and tilt angle of the agglomerating disc had been determined, the inventors proceeded to determine the minimum water range required to achieve adequate agglomeration.

[0096]

[0068] For these purposes, the inventors evaluated three levels of water dosage and rotation speeds, using two samples of copper mine tailings (T1 and T2), and maintaining an angle of inclination of approximately 45°. The results obtained are shown in Table No. 2.

[0097] Table No. 2: Size ranges of the agglomerates obtained under different operating conditions.

[0098]

[0099]

[0069] The results obtained through this experiment allowed the inventors to conclude that the various process parameters were directly interrelated and that further adjustments were necessary to obtain agglomerates with the desired characteristics. Among other reasons, the results showed a high presence of very fine particle size agglomerates and low size homogeneity.

[0100]

[0070] Although these experiments were not conclusive per se, they allowed the inventors to determine that a higher water dosage tended to increase the average size of the agglomerates, while increasing the rotation speed of the disc resulted in a reduction in that size. Example No. 4: Evaluation of agglomeration process with cement.

[0101]

[0071] The inventors replicated the previously conducted agglomeration tests, incorporating Portland cement as an additive to contribute to the solidification and physicochemical stabilization of the tailings, thus ensuring that the agglomerates meet the necessary characteristics for their subsequent use as construction material. They also measured the operating time required in the process to obtain agglomerates with spherical geometry and uniform size.

[0102]

[0072] For these experimental tests, the inventors kept the mass of copper mine tailings constant, along with a cement ratio of approximately 10% w / w, an angle of inclination of approximately 45°, and a rotation speed of approximately 21 rpm. The tailings were previously sieved to obtain a maximum particle size of 2 mm. The results obtained are shown in Table 3.

[0103] Table No. 3: Size ranges of the agglomerates obtained under different operating conditions and using cement as an additive.

[0104]

[0105]

[0073] The results obtained showed that the size of the agglomerates produced varies depending on both the operating time and the amount of binder (water) used. The inventors observed that an increase in the water dosage or in the operating time resulted in a slight increase of at least 1 mm in the maximum size of the agglomerates.

[0106]

[0074] Based on these results, the inventors concluded that it was feasible to obtain physically stabilized tailings agglomerates using a mixture of water and cement. Subsequently, the inventors conducted further experimental tests to adjust all the critical parameters (operating time, amount of binder, and rotation speed) and achieve an optimal combination.

[0107] Example No. 5: Evaluation of product particle size distribution.

[0108]

[0075] The inventors performed granulometric characterization tests to evaluate the size of the agglomerates produced in accordance with standard NCh165. For this purpose, they used a sample of copper mine tailings T1 and Portland cement in a proportion of approximately 10% w / w, with a disc inclination angle of approximately 45°, water in a proportion of approximately 17% w / w, and three rotation speeds (approximately 16, 21, and 28 rpm). The tailings were previously sieved to obtain a maximum particle size of 2 mm. The results obtained are shown in Figure 2.

[0109]

[0076] Based on the results obtained, the inventors determined that a speed of approximately 21 rpm was optimal for agglomerate formation, considering a water content of approximately 17% w / w and an inclination angle of approximately 45°. The particle size distribution showed a higher mass concentration in the central sieves (approximately 48%), specifically in the fractions corresponding to approximately 12.7, 9.5, and 6.4 mm.

[0110]

[0077] These results showed that the particle size distribution of the agglomerates resembled that of gravel, indicating that the materials produced by the described process can be used as a substitute for this material in concrete mixtures. Example No. 6: Product density evaluation.

[0111]

[0078] To evaluate the density variation of the agglomerates formed under different operating conditions, the inventors conducted an additional set of tests. For this, they used Portland cement at a ratio of approximately 10% w / w, water at a ratio of approximately 17% w / w, two rotation speeds (approximately 16 and 21 rpm), and different rotation angles (approximately 35°, 40°, and 45°). The copper mine tailings were previously sieved to obtain a maximum particle size of 2 mm. The tests were performed at regular 7-day intervals from the day the agglomerates were manufactured until 28 days later. The results obtained are shown in Table 4.

[0112] Table No. 4: Average density of the agglomerates manufactured at different rotation speeds and angles of inclination.

[0113]

[0114]

[0079] Based on the results obtained, the inventors determined that the operating variables (angle of inclination and rotation speed) did not exert a significant influence on the density of the agglomerates. In fact, they observed that the density remained practically constant throughout the 28 days evaluated, with a slight, but not significant, progressive decrease.

[0115]

[0080] Additionally, the inventors conducted three tests maintaining an angle of inclination of approximately 40° and a rotation speed of approximately 21 rpm, but varying the cement proportion to approximately 10%, 15%, and 20% w / w. The results obtained are shown in Table No. 5. Table No. 5: Average density of the agglomerates manufactured with different cement contents in the mixture.

[0116]

[0117]

[0081] Based on the results obtained, the inventors determined that the variation in cement content also did not produce significant differences in the density of the agglomerates during the 28-day evaluation period.

[0118]

[0082] These findings allowed us to conclude that both the operating conditions evaluated and the percentage of cement used have a minimal impact on the final density of the aggregates, which consolidates the robustness of the process under the selected parameters.

[0119] Example No. 7: Evaluation of fine material smaller than 0.075 mm.

[0120]

[0083] Prior to the agglomeration process, the inventors characterized the copper mine tailings used, determining that it contained approximately 65% ​​fine particulate matter smaller than 0.075 mm. This value served as a reference to evaluate the capacity of the proposed method to retain or reduce the presence of fines in the resulting agglomerates.

[0121]

[0084] With the objective of evaluating the quality of the generated agglomerates for use as a possible substitute for aggregates in construction materials, the inventors carried out tests focused on analyzing the percentage of fine particulate material resulting from washing the product.

[0122]

[0085] For this, Portland cement was used at a proportion of approximately 10% w / w, a rotation angle of approximately 40°, two rotation speeds (approximately 21 and 28 rpm), and water at proportions of approximately 16.7% and 17% w / w. The copper mine tailings were previously sieved to obtain a maximum particle size of 2 mm. The results obtained are shown in Table 6. Table 6: Fine particulate material less than 0.075 mm produced by agglomerates manufactured at different rotation speeds and water dosages.

[0123]

[0124]

[0086] Based on the results obtained, the inventors determined that the amount of remaining fine particulate matter was low. In fact, they observed that the percentage of fines was around 5% after 7 days, increasing slightly in the samples processed at a speed of approximately 28 rpm.

[0125]

[0087] The inventors also evaluated the influence of the cement content in the mixture at approximately 10%, 15%, and 20% w / w, keeping the water content constant at approximately 17% w / w and using a rotation speed of approximately 21 rpm. The tests were performed at intervals of 7, 14, and 28 days after the production of the aggregates. The results obtained are shown in Table 7.

[0126] Table No. 7: Fine particulate matter less than 0.075 mm produced by agglomerates manufactured with different cement contents in the mixture.

[0127]

[0128]

[0088] Based on the results obtained, the inventors determined that the greatest changes in the amount of fine particulate matter were observed at 7 and 28 days. In general, a decrease in the amount of fines was evident as the cement content in the mixture increased, indicating greater internal cohesion of the aggregates.

[0129]

[0089] A reduction in fines was also observed over time, especially in formulations with a higher cement content. This decrease is attributed to the progressive increase in the mechanical strength of the aggregates during the curing process, which allows for better retention of the fine particles within their structure.

[0130]

[0090] These findings allowed the inventors to conclude that the agglomerates obtained by the proposed method exhibit good fines retention capacity and a stable structure, which supports the technical effectiveness of the agglomeration process developed.

[0131] Example No. 8: Evaluation of the hardness of agglomerates by means of compression testing.

[0132]

[0091] In order to evaluate the behavior of the agglomerates during storage and their applicability as a construction material, the inventors performed compressive strength tests, measuring the maximum load supported by each agglomerate until failure. For this purpose, they used agglomerate samples of different sizes (approximately 8, 11, and 16 mm) produced from two samples of copper mine tailings (T1 and T2) under the following operating conditions: Portland cement in proportions of approximately 5%, 10%, and 20% w / w, water in a proportion of approximately 17% w / w, an angle of inclination of approximately 40°, a rotation speed of approximately 21 rpm, a maximum initial particle size of 2 mm, and an operating time of 10 minutes. The tests were performed 7, 14, and 28 days after agglomerate production. The results obtained are shown in Tables 8, 9, and 10.

[0133] Table No. 8: Maximum load of agglomerates with an average diameter of 8 mm.

[0134]

[0135] Table No. 9: Maximum load of agglomerates with an average diameter of 11 mm.

[0136]

[0137] Table No. 10: Maximum load of agglomerates with an average diameter of 16 mm.

[0138]

[0139]

[0092] From the results obtained, the inventors determined that, in all cases, an increase in the particle size used, the drying time, and the amount of cement in the mixture resulted in a significant increase in the maximum load supported.

[0140]

[0093] These findings allowed the inventors to conclude that the agglomerates obtained by the proposed method exhibit adequate mechanical resistance, which supports their potential use as a construction material.

[0141] Example No. 9: Validation of the use of agglomerates as a substitute in concrete specimens.

[0142]

[0094] Finally, to validate the feasibility of using tailings-based aggregates (composed of tailings, cement, and water) as partial replacements in concrete manufacturing, the inventors prepared experimental samples using a water-cement ratio of approximately 0.6. The concrete samples were manufactured with 50% replacement of the total volume of aggregates (gravel and sand), using copper mine tailings-based aggregates synthesized with varying amounts of cement in the mix. Concrete specimens were then made from the prepared mix and tested using unconfined compression and splitting tensile strength tests. The tests were performed after seven days of curing. The results obtained are shown in Table 11.

[0143] Table No. 11: Compressive and tensile strengths obtained by concrete specimens using aggregates with different cement content.

[0144]

[0145]

[0095] The results obtained demonstrated that the replacement of agglomerated materials in the concrete specimens is technically feasible and meets the requirements established by the applicable regulations. Specifically, the inventors determined a compressive strength of 17.1 MPa and a tensile strength of 1.9 MPa at seven days when 50% of the volume of conventional gravel and sand was replaced with the agglomerated tailings material containing cement in a proportion of approximately 20% w / w, and with a water-cement ratio of approximately 0.6.

Claims

LIST OF CLAIMS 1. A method for the production of agglomerates from tailings from metallic mining, CHARACTERIZED in that it comprises at least the following steps: a. Sieve the tailings to obtain particles no larger than 2 mm; b. Add cement to the sieved tailings in a proportion of between 5 and 20% w / w, forming a mixture of solids; c. Add the solids mixture to an agglomerating disc set at an angle of between 20 and 50°; d. Rotate the agglomerating disc at a speed of between 10 and 28 rpm, until a homogeneous mixture is obtained; e. Add water to the homogeneous mixture in a proportion of between 10 and 20% w / w; and f. Continue rotation until agglomerates of the desired size are obtained.

2. The method according to claim 1, CHARACTERIZED in that in step (b), the proportion in which cement is added to the screened tailings is approximately 10% w / w.

3. The method according to claim 1, CHARACTERIZED in that in step (c), the agglomerating disc is configured at an angle of approximately 45°.

4. The method according to claim 1, CHARACTERIZED in that in step (d), the speed of the agglomerating disc is approximately 21 rpm.

5. The method according to claim 1, CHARACTERIZED in that in step (e), water is added to the homogeneous mixture in a proportion of approximately 17% w / w.

6. The method according to claim 1, CHARACTERIZED in that the agglomerates obtained have a size of between 5 and 25 mm.

7. The method according to claim 1, CHARACTERIZED in that the resulting agglomerates are subjected to a drying process.

8. The method according to claim 7, CHARACTERIZED in that the drying is carried out until the moisture content of the agglomerates is between 0.5 and 5%.

9. The method according to claim 7, CHARACTERIZED in that the drying is carried out at a temperature between 15 and 40°C.

10. An agglomerate to be used as a replacement for aggregates, CHARACTERIZED in that it comprises: Tailings; and Cement. Where: The cement is present in a proportion of between 5 and 20% w / w; and The resulting agglomerates have a size of between 5 and 25 mm.

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