Abstract Millions of tons of mine tailings are generated worldwide annually. Since many valuable metals such as Ag, Cu, Pb, Zn, Au and Ni are usually incorporated into sulphidic minerals, a large proportion of the tailings generated contain high amounts of sulphates and heavy metals. Some of these tailings are used as paste backfill material at mining sites, but large amounts are still being deposited into the tailings dams under water coverage. Sulphidic minerals are stable underground but after mining of the ore and several processing steps these minerals can be oxidized when they come into contact with water and air. This oxidation generates acid and thus reduces the pH of the surrounding environment. Furthermore, the heavy metals present in the mine tailings can be leached into the environment. This phenomenon, called Acid Mine Drainage (AMD), is one of the most critical environmental issues related to the management of sulphidic-rich tailings. Since AMD generation can still occur hundreds of years after closure of the mine, the mine tailings need stable, sustainable and economically viable management methods in order to prevent AMD production in the long term. The aim of this PhD thesis was to study various solidification/stabilization (S/S) methods for the immobilization of sulphidic mine tailings. The main focus was to develop a suitable chemical environment for achieving effective heavy metal (mainly arsenic) and sulphate immobilization while simultaneously ensuring good mechanical properties. Three treatment methods were tested: alkali activation, stabilization using hydrated lime (Ca(OH)2) and blast furnace slag (GBFS), and calcium sulphoaluminate-belite (CSAB) cement stabilization. The mine tailings used in this study contained large amounts of sulphates and heavy metals such as Cr, Cu, Ni, Mn, Zn, V and As. The leaching of arsenic and sulphates from powdered tailings exceeded the legal limits for regular and inert waste. All treatment methods were found to generate a hardened matrix that was suitable for use as a backfilling or construction material, but the calcium-based binding system was the most suitable for effective immobilization of all the heavy metals (including arsenic) and the sulphates. Precipitation in the form of calcium sulphates/calcium arsenate and the formation of ettringite are the main stabilization methods employed in calcium-based stabilization/solidification (S/S) systems. Some evidence of physical encapsulation occurring simultaneously with chemical stabilization was noted. These results can be exploited further to develop more sustainable mine tailing management systems for use in the future. The tailings could be stored in a dry landfill area instead of in tailing dams, and in this way a long-term decrease in AMD generation could be achieved, together with a high potential for recycling. / Tiivistelmä Monet arvometallit kuten kulta, kupari ja nikkeli ovat sitoutuneena sulfidipitoisiin mineraaleihin. Louhittaessa ja rikastettaessa näitä sulfidimineraaleja syntyy miljoonia tonneja sulfidipitoisia rikastushiekkoja vuosittain. Rikastushiekat voivat sisältää myös runsaasti erilaisia raskasmetalleja. Osa rikastushiekoista hyödynnetään kaivostäytössä, mutta suurin osa rikastushiekoista läjitetään edelleen ympäristöön rikastushiekka-altaisiin veden alle. Kun sulfidipitoinen malmi kaivetaan ja käsitellään, sulfidiset mineraalit hapettuvat ollessaan kosketuksissa veden ja hapen kanssa. Hapettuessaan ne muodostavat rikkihappoa, laskien ympäristön pH:ta jolloin useimmat raskasmetallit liukenevat ympäristöön. Muodostuvia happamia kaivosvesiä voi syntyä vielä pitkään kaivoksen sulkemisen jälkeen ja ovat näin ollen yksi suurimmista kaivosteollisuuteen liittyvistä ympäristöongelmista. Lisäksi suuret rikastushiekka-altaat voivat aiheuttaa vaaraa myös ihmisille, mikäli altaan rakenteet pettävät. Rikastushiekkojen kestäviä ja ympäristöystävällisiä varastointimenetelmiä täytyy kehittää, jotta näitä ongelmia voidaan tulevaisuudessa ehkäistä. Tässä työssä tutkittiin menetelmiä, joilla kultakaivoksella syntyvät sulfidipitoiset vaaralliseksi jätteeksi luokitellut rikastushiekat saataisiin stabiloitua tehokkaasti. Työssä keskityttiin kolmeen erilaiseen menetelmään: alkali-aktivointiin, stabilointiin kalsiumhydroksidin ja masuunikuonan avulla ja stabilointiin CSAB sementin avulla. Valmistettujen materiaalien mekaanisia ja kemiallisia ominaisuuksia arvioitiin. Tavoitteena oli ymmärtää, miten eri menetelmät soveltuvat raskasmetallien (erityisesti arseenin) ja sulfaattien sitoutumiseen ja mikä on eri komponenttien rooli reaktioissa. Alkali-aktivoimalla rikastushiekkaa sopivan sidosaineen kanssa saavutettiin hyvät mekaaniset ominaisuudet ja useimmat haitta-aineet sitoutuivat materiaaliin. Ongelmia aiheuttivat edelleen sulfaatit ja arseeni. Kalsiumpohjaiset menetelmät sitoivat raskasmetallit (myös arseenin) ja sulfaatit tehokkaimmin. Sulfaatit ja arseeni saostuivat muodostaen niukkaliukoisia komponentteja kalsiumin kanssa. Samanaikaisesti rakenteeseen muodostui ettringiittiä, jolla on tutkitusti hyvä kyky sitoa erilaisia raskasmetalleja rakenteeseensa. Raskasmetallit myös kapseloituivat rakenteen sisään. Työn tuloksia voidaan hyödyntää, kehitettäessä rikastushiekkojen turvallista varastointia. Kun materiaalille saavutetaan riittävän hyvä lujuus ja kemiallinen stabiilius, rikastushiekat voitaisiin läjittää tulevaisuudessa kuivalle maalle altaan sijaan. Näin vältyttäisiin rikastushiekka-altaiden rakentamiselta ja voitaisiin vähentää happamien kaivosvesien muodostumista pitkällä ajanjaksolla. Saavutettujen tulosten perusteella rikastushiekkoja voidaan mahdollisesti tulevaisuudessa hyödyntää myös erilaisissa betonin tapaisissa rakennusmateriaaleissa.

Les résidus miniers représentent les sous-produits minéraux finement broyés issus des procédés de traitement et d’enrichissement des minerais. Durant l’exploitation d’une mine, ces rejets sont habituellement transportés sous formes de pulpes et entreposés en surface dans des aires d’accumulation appelées parcs à résidus. Ces derniers sont des ouvrages, le plus souvent, difficiles à gérer et coûteux à restaurer. Ils sont à l’origine d’une multitude d’impacts environnementaux qui dépendent principalement de leur potentiel polluant, de leur mode de gestion, de la stabilité physique des infrastructures de confinement et des conditions climatiques spécifiques au site d’entreposage. Dans ce contexte, plusieurs études ont été entreprises afin de développer de nouvelles techniques qui permettraient une gestion effective et durable de ces sous-produits minéraux. Des voies de valorisation dans le domaine du BTP ont ainsi été explorées. Les résultats ont montré la possibilité de réutilisation de certains rejets miniers comme matériaux cimentaires et additifs pour mortiers ou béton. Toutefois, la majorité des formulations proposées n’ont pas dépassé le stade du laboratoire. De plus, l’utilisation des rejets miniers comme matériaux de construction est encore sujet à des difficultés en matière d’acceptabilité sociale et à d’innombrables préoccupations, notamment leur stabilité physico-chimique et leur éco-compatibilité. En parallèle, l’utilisation artisanale et non contrôlée des rejets miniers à faibles teneurs en sulfures comme matériaux de construction est en pleine croissance dans quelques pays tel que le Maroc. En effet, à proximité de quelques sites miniers abandonnés, ces rejets sont considérés comme des sables naturels et sont utilisés pour la confection de mortier de finition et de surfaçage des murs d’habitations. Ce recyclage artisanal peut constituer des risques mécaniques et environnementaux liés surtout à la non-conformité mécanique de ces matériaux et à la présence de concentrations non négligeables de métaux résiduels dans les rejets miniers. L’objectif de ce travail de recherche est donc d’évaluer l’impact de l’utilisation actuelle de deux rejets miniers marocains (Zeida et Mibladen), communément utilisés comme agrégats dans la région de la haute-Moulouya, sur les propriétés physico-chimiques des mortiers de finition et d’étudier, sur le long terme, le relargage des métaux lourds en scénario de lixiviation. Ce travail se donne aussi comme objectif spécifique, d’étudier la faisabilité technique d’utilisation des rejets miniers à faible teneur en sulfures comme substituant au sable conventionnel pour la confection de mortiers d’enduit et de maçonnerie. / Mine tailings represent the finely ground industrial by products generated throw beneficiation of ore minerals. During mine exploitation, these tailings are generally transported in slurry form to large storage facilities, called tailings ponds or impoundments. These facilities are, in most cases, difficult to manage and expensive to rehabilitate. They are responsible for the generation of important environmental impacts and significant ecological disruptions, depending on their pollution potential, management technique, physical stability and the climate conditions. In this context, numerous studies have been conducted to develop new techniques for a sustainable management of mine tailings. The feasibility of reusing some tailings in the construction sector as cementing materials and additives for mortars or concretes were successfully achieved. However, the majority of the conducted studies are still at laboratory stages. Moreover the reuse of tailings as construction material is yet subject of numerous difficulties in term of social acceptance. Various parameters are also of concern, especially the physical and chemical stability of tailings as well as their eco-compatibility. In parallel, the uncontrolled reuse of low sulfide tailings as construction material is increasing in some developing countries (e.g. Morocco). In fact, nearby some abandoned mine sites, these tailings are considered as natural sands and are used for the manufacture of surface finishing mortars. This traditional recycling may constitute mechanical and environmental risks, principally related to tailings mechanical unconformity and to their non-negligible residual metal concentrations. Therefore, the aim of the current research is to evaluate the actual impact of two Moroccan mine tailings (named Zeida and Mibladen), commonly used as aggregates in the Upper-Moulouya region, on the mechanical properties of mortars and on their long term environmental behavior. This work has also as specific aim, to study the technical feasibility of using low sulfide tailings as sand substitute for the manufacture of rendering and masonry mortars. To attain this aim, a thorough characterization of the physical, chemical and mineralogical properties as well as the geochemical behavior of mine tailings was carried out. Mechanical properties of tailings-based mortars were then measured and compared to reference samples (sand-based mortars) using different tests such as setting time, entrained air volume and compressive strength. In parallel, mortars durability and hydration products were evaluated by mean of durability tests (wetting drying cycles, sulfate attack and acid rain simulation) and analytical methods (scanning electron microscopy, X-ray diffraction and thermo-gravimetric analysis). Finally, mortar samples were submitted to various leaching tests to evaluate the pollution potential of these matrices.

La poursuite est une figure qui accompagne le cinéma depuis ses débuts jusqu’à en devenir, presque, la forme archétypale. Elle a constitué le principal mode de linéarisation des formes courtes du cinéma des premiers temps et reste un mode habituel de structuration des grands récits. Présence et absence de poursuites, existence sous des formes apparentées telles que la filature ou la déambulation, sont des éléments de caractérisation des films particulièrement intéressants. Leurs conditions d’élaboration et de réception sont à replacer dans leur contexte et à étudier dans une perspective d’une histoire des formes. Observer la place qui est donnée à la poursuite par quatre réalisateurs français, d’époques différentes, Louis Feuillade, René Clair, Jean-Pierre Melville et Philippe de Broca, conduit à mettre en évidence sa pérennité. L’analyse comparée de sa mise en scène chez ces cinéastes que tout, parfois, semble opposer, permet d’utiliser la poursuite comme un critère de distinction pour mettre en évidence la valeur symbolique et la signification intrinsèque de cette figure, tant comme forme esthétique que comme forme anthropologique. / The Notion of Chasing has been part of cinema life from the very beginning, so much so that it has almost become an archetypal form. It was the principal method of moving the plot forward in short films when cinema began and remained a normal method of structure for feature-films. The presence, or absence of chasing whether in a related form such as tailing someone or on foot, is an extremly interesting element of film characterisation. The condition of its elaboration and of reception must be put back into context and studied with the perspective of the history of the form. Studying the importance given to chasing by four French film directors of different eras, Louis Feuillade, René Clair, Jean-Pierre Melville et Philippe de Broca, will bring out the form’s perennity. Likewise comparing the director’s management of such scenes, especially since these four can on occasion seem like opposites, enables one to use chasing as an differentiating criteria that is particulary important when bringing out the value, both symbolic and intrinsic, of this form as an aesthetic and anthropological form.

La presente investigación busca determinar la problemática es determinar si existe una relación positiva entre las acciones de CRM y la compra online. La metodología que se utilizará para esta investigación busca comprobar las hipótesis mediante una encuesta online dirigida a 300 personas, en relación a la muestra esta estará conformada por varones o mujeres de 18 a 25 años del NSE B y C que residan en Lima Metropolitana. De esta manera, se busca comprobar que las acciones de CRM impactan directamente en la compra online. En ese sentido, se busca concluir resultados positivos en cuanto a nuestra metodología e hipótesis, las cuales determinarán el efecto positivo de implementar acciones de CRM en el retail de moda. / This research seeks to determine the problem is to determine if there is a positive relationship between CRM actions and online shopping. The methodology that will be used for this research seeks to verify the hypotheses through an online survey directed to 300 people, in relation to the sample this will be made up of men or women between 18 and 25 years of age from NSE B and C who reside in Metropolitan Lima. In this way, it seeks to verify that CRM actions have a direct impact on online shopping. In this sense, we seek to conclude positive results regarding our methodology and hypotheses, which will determine the positive effect of implementing CRM actions in fashion retail. / Trabajo de investigación

Gas chromatography (GC) is an analytical chemistry tool used to determine the chemical composition of a gas sample by separating sample analytes as they travel through a GC column. Recent efforts have been made to understand and control gas chromatography separations with a negative thermal gradient on the column. The present work presents results from thermal gradient GC separations on two GC columns in different configurations (serpentine and radial) in a stainless-steel plate. Methods to fabricate the GC systems capable of isothermal, temperature programmed and thermal gradient separations are presented. Isothermal experimental data from the serpentine column were used to fit retention and dispersion parameters in a transport model that simulates GC separation for hydrocarbons C12-C14. Transport model simulated retention times and peak widths matched experimental values well for isothermal, temperature programmed and thermal gradient separations. The validated transport model was used to study the effect of static (not varying temporally) thermal gradients on GC separations with varying injection widths, injection band shapes and stationary phase thickness. Resolution results from different heating conditions were considered comparable if retention times for each analyte were within 5%. An optimal, static thermal gradient is shown to reduce analyte band spreading from axially-varying velocity gradients with resolution improvements over isothermal separations of up to 8% for analytes with similar retention factors. Static thermal gradients have a larger effect on fronting peak shape than tailing peak shape. Stationary phase distribution acts similar to a velocity gradient and can be corrected by a thermal gradient. Another transport model was created from isothermal experimental data on a commercial column for hydrocarbons C12-C20. An optimal, static thermal gradient does not improve resolution for all analyte pairs. An optimal, dynamic (varying tempo-rally) thermal gradient is created by uniformly increasing the temperature on an optimal, static thermal gradient. Improvements in resolution of up to 20% are achievable over temperature programmed GC separation. A dynamic thermal gradient can also correct for a poor sample injection by creating a temperature trap at the beginning of the column.

[pt] Este trabalho apresenta a utilização de métodos de equilíbrio limite em conjunto com métodos numéricos pela abordagem probabilística, para avaliação da estabilidade de uma barragem de rejeitos de mineração de ferro situada no quadrilátero ferrífero, no Estado de Minas Gerais. Foram conduzidas análises fazendo uso dos métodos de Bishop Simplificado (1955) e Morgenstern e Price (1965), além de análises numéricas de tensão vs deformação pelo método dos elementos finitos. Os campos de poropressão gerados no modelo numérico em dois momentos distintos da obra foram exportados para os modelos de equilíbrio limite, de forma que ambas análises fossem realizadas em condições piezométricas similares. Para as análises probabilísticas foram adotados os métodos FOSM (First Order Second Moment) e Monte Carlo. São apresentandos os conceitos básicos de análises de estabilidade determinísticas e probabilísticas, abrangendo os métodos de cálculo de FS, fundamentos de probabilidade e estatística e conceitos de modelagem numérica. Este estudo aborda também os princípios construtivos de barragens de rejeito de mineração, além da aplicação dos métodos probabilísticos para avaliação da estabilidade de uma barragem de rejeitos, construída pelo método de jusante. Os resultados indicaram que a consideração de uma superfície de ruptura livre foi fator preponderante na influência dos parâmetros na PR (Probabilidade de Ruptura). Concluiu-se também que os método de cálculo de FS teve maior influência no valor da PR do que as condições piezométricas da fundação. / [en] This work presents the use of limit equilibrium (LEM) and numerical methods by the probabilistic approach, in order to evaluate the stability of an iron ore tailings dam located in Minas Gerais s iron quadrangle. LEM analyzes were carried out using the Simplified Bishop (1955) and Morgenstern and Price (1965) methods, in addition to stress vs strain analyzes with the finite element method. The pore pressure fields generated in the numerical model at two distinct construction stages were exported to the limit equilibrium models in order to guarantee that both analyzes were performed on the same piezometric conditions. For the probabilistic analyzes the FOSM (First Order Second Moment) and Monte Carlo methods were applied. The basic concepts of deterministic and probabilistic stability analysis are presented together with the fundamentals of statistics and probability, FoS (Factor of Safety) calculation methods, as well as numerical modeling concepts. This work also addresses the definition and construction principles of tailings dams. This study presents an application of probabilistic methods to assess the stability of a tailings dam built and heightened by the downstream method. The results indicate that the consideration of a free failure surface was the decisive factor to the magnitude of the influence of each parameter on the PF (Probability of Failure). It was also concluded that the FoS calculation methods had a greater influence on the PF than the foundation s piezometric conditions.

[pt] O gerenciamento e estocagem dos residuos de mineração apresentam desafios constantes devido às crescentes demandas do setor, dessa forma, o aperfeiçoamento dos processos de gestão dos rejeitos e a otimização da capacidade de estocagem dos reservatórios são fundamentais para a viabilidade de um empreendimento de exploração de recursos minerais. O presente trabalho apresenta a metodologia utilizada para avaliação do processo de ressecamento de rejeito da lavagem de bauxita da Mineração Rio do Norte, sendo proposta a execução de dois reservatórios experimentais, em escala piloto, possibilitando o monitoramento do comportamento de ressecamento do rejeito in loco e a cxecução de ensaios em laboratório. A proposta do estudo é avaliar o comportamento do rejeito quando disposto em diferentes espessuras de camadas, incluindo aspectos de condições climáticas e tempo de secagem. O objetivo foi calibrar o modelo de enchimento e otimizar a área dos reservatórios contidos no sistema de contenção de rejeitos da MRN, aperfeiçoando a previsibilidade do final da vida útil das estruturas e maior assertividade do balanço de massas no longo prazo. Os estudos de campo e laboratório consistiram na disposição e monitoramento de camadas com 0,50 m e 0,80 m. Dessa forma, foi possível a avaliacão dos teores de sólidos ao final do periodo de secagem das camadas dispostas, avaliar as curvas de enchimento e recalque do rejeito, medir os ângulos de repouso no momento da disposição e após periodo de ressecamento e analisar a morfologia e desenvolvimento das trincas de contração. Com base nos resultados laboratoriais e de campo obtidos nesse trabalho, conclui-se que o comportamento do processo de ressecamento do rejeito é influenciado por uma série de fatores, podendo citar a permeabilidade do fiundo dos reservatórios as condições climáticas (incidência pluviométrica e taxa de evaporação) como os mais impactantes ao processo. No trabalho não foi observado uma grande diferença do comportamento de rejeito para as camadas de 0,50 cm e 0.80 cm. / [en] The management and storage of mining waste present constant challenges due tothe increasing demands of the sector. Therefore, improving waste managementprocesses and optimizing the storage capacity of reservoirs are fundamental to theviability of a mineral resource exploration project. This study presents themethodology used to evaluate the desiccation process of washed bauxite tailings atMineração Rio do Norte (MRN). The implementation of two experimentalreservoirs at a pilot scale is proposed, allowing on-site monitoring and laboratorytests for the tailings desiccation behavior. The objective of the study is to assess thetailings behavior when disposed in different layer thicknesses, considering aspectssuch as weather conditions and drying time. The aim was to calibrate the fillingmodel and optimize the area of the reservoirs within MRN s tailings storage facility,thus improving the predictability of the structures end-of-life and enhancing theaccuracy of long-term mass balance. Field and laboratory studies involved thedeposition and monitoring of layers with thicknesses of 0.50 m and 0.80 m. Thisenabled the evaluation of the solids content at the end of the drying period.assessment of filling and settlement curves, measurement of the angle of repose atthe time of deposition and after the drying period, and analysis of crack morphologyand development. Based on the field and laboratory results obtained in this study,it can be concluded that the behavior of the tailings desiccation process is influencedby several factors. The permeability of the reservoir bottom and weather conditions(rainfall and evaporation rate) are identified as the most impactful to the process.No significant difference in the behavior of the waste was observed between the 0.50 cm and 0.80 cm layers.

No description available.

Syftet med denna studie har varit att undersöka hur företag samlar in och utnyttjar kundinformation mellan försäljningskanalerna. Men även att utreda motiven bakom att bli en multikanalåterförsäljare samt produkttypens roll i beslutet. En kvalitativ fallstudie med semistrukturerade intervjuer har tillämpats, där fyra företag och en expert deltagit. Studien har visat att information om kunden har varit värdefull och har använts emellan handelskanaler för att anpassa butikens sortimentsmix, skapa välgrundade kampanjer och styra kunder till butik. De mindre företagen, sett till omsättning, har haft mer användning av kundinformation vid beslutet att öppna fysiska butiker än de större. Motivationen bakom att bli multikanalhandlare har varit potentialen att nå fler kunder men även bättre kundfokus. Andra faktorer än produkttyp har varit av intresse för företagen vid öppnandet av de fysiska butikerna men arbetet med returer har visat att produkttyp kan spela roll. / The study investigates how companies gather and use customer information between sales channels. But it will also investigate the motive behind expanding to multichannel retailing and the role of the product type in that decision. A qualitative case study with semi structured interviews has been applied, were four companies and one expert has participated. The study has shown that data about the customer has been valuable and has been used between sales channels to adjust the stores product mix, create well-founded campaigns as well as directing customers to the stores. The smaller companies, in terms of turnover, used a greater amount of customer information in the decision of adding stores than the larger ones. The motivation behind going multichannel has been the potential of reaching more customers but also getting better customer focus. Other factors than product type has been of interest to the companies when the stores were added, but the work around product returns has shown that the product type can matter.

[pt] O presente trabalho estudou o comportamento de rejeitos de minério de ferro e de ouro, reforçados com fibras de polipropileno, com o objetivo da aplicabilidade destes compósitos em aterros (pilhas) de rejeitos de mineração. As fibras foram distribuídas de forma aleatória nos rejeitos (matriz) em um teor de 0.5 por cento em relação ao peso seco da matriz. Os rejeitos de minério de ferro e de ouro são classificados como uma areia siltosa e uma argila siltosa, respectivamente. O programa experimental consistiu em ensaios triaxiais convencionais drenados e não drenados (tensões efetivas de confinamento de 50, 100, 200 e 400 kPa) em amostras não reforçados e reforçados com fibras. Ensaios de cisalhamento direto com superfície polida (tensões normais de 25, 50, 100, 200 e 400 kPa) foram realizados para determinar a influência do reforço na fase residual dos compósitos. Ensaios de Microscopia Eletrônica de Varredura (MEV) foram realizados para visualizar a interação fibra-matriz. A análise global dos resultados permitiu mostrar que fibras de polipropileno não modificam o comportamento elastoplástico do rejeito de minério de ferro, porém no rejeito de minério de ouro o comportamento muda para elastoplástico de enrijecimento. A resistência ao cisalhamento incrementou em ambos os rejeitos reforçados, com um ganho mínimo equivalente ao dobro da tensão cisalhante dos rejeitos sem reforço. Com relação à variação volumétrica, o rejeito de minério de ferro apresenta um comportamento dilatante e a adição de fibras incrementa esse comportamento. No rejeito de minério de ouro observa-se que a tendência volumétrica inicial é de contração e depois apresenta uma leve dilatância, porém, com a adição de fibras, o comportamento dilatante é eliminado. Em conclusão, a aplicabilidade das fibras de polipropileno se mostra como alternativa de reforço e melhoria do comportamento geotécnico dos rejeitos de mineração estudados. / [en] The objective of this work is to study the behavior of iron and gold mine tailings reinforced with polypropylene fibers with the objective of the applicability of these composites in landfills (piles) of mine tailings. The fibers were randomly distributed in the mine tailings (matrix), where was used a content of 0.5 percent in relation to the dry weight of the matrix. The iron and gold mine tailings are classified as a silty sand and a silty clay, respectively. The experimental program consisted of conventional drained and undrained triaxial tests (effective confinement stresses of 50, 100, 200 and 400 kPa) in non-reinforced and reinforced samples. Direct shear tests with a polished surface (normal stresses of 25, 50, 100, 200 and 400 kPa) were performed to determine the influence of reinforcement on the residual phase of the composites. Scanning Electron Microscopy (SEM) tests were performed to visualize the fiber-matrix interaction. The global analysis of the results allowed to show that polypropylene fibers do not modify the elastoplastic behavior of the iron mine tailings, but in the gold mine tailings the behavior changes to the strain hardening elastoplastic. Shear strength increased in both reinforced tailings, with a minimum gain equivalent to twice the shear stress of non-reinforced tailings. The strength parameters in the drained, undrained and residual condition of both mine tailings were increased with the addition of fiber. Regarding the volumetric variation, the iron mine tailings exhibits a dilative behavior and the fiber addition increases this behavior. In the gold mine tailings, it is observed that the initial volumetric tendency is contractive and then presents a slight dilatancy, however, with the fiber addition, the dilative behavior is eliminated. In conclusion, the applicability of the polypropylene fibers is showed as an alternative of reinforcement and improvement of the geotechnical behavior of the studied tailings.