Marble Processing Plant Research Articles

Systematic assessment of electrocoagulation for the treatment of marble processing wastewater

In this study, the treatability of marble processing wastewater by electrocoagulation using aluminum and iron electrodes was investigated. The sample used was from the marble-processing plant in Sivas and its turbidity, suspended solids, chemical oxygen demand and total solids concentrations were about 1,914 NTU, 2,904, 150 and 4,750 mg/L, respectively. The effects of various operating parameters such as initial pH, current density and electrolysis time on turbidity, suspended solids, chemical oxygen demand and total solids removal efficiencies were investigated. The settling characteristics of waste sludge produced and energy and electrode consumption were also determined. The optimum values of initial pH, current density and electrolysis time in electrocoagulation studies carried out using aluminum electrode were found to be 7.8, 30 A/m2 and 5 min, respectively. Under these conditions, the removal efficiencies obtained for turbidity, suspended solids, chemical oxygen demand and total solids were 98.5, 99.2, 55.2 and 92.4 %, respectively. Corresponding energy and electrode consumptions were 0.143 kWh/kg SS and 0.010 kg Al/kg SS. For iron electrode, the optimum parameter values were found to be 7.8 pH, 20 A/m2 and 5 min, respectively. Under these conditions, removal efficiencies for turbidity, suspended solids, chemical oxygen demand and total solids were determined as 94.3, 99.1, 54.2, and 96.1 %, respectively. Energy and electrode consumptions were 0.0571 kWh/kg SS and 0.0206 kg Fe/kg SS, respectively. Settling characteristics of sludge produced during experiments carried out using both aluminum and iron electrodes were fairly good. The results showed that electrocoagulation method can be used efficiently for the treatment of marble processing wastewater under proper operating conditions.

Recycling studies of marble processing waste: Composites based on commercial epoxy resin

Marble waste was obtained from marble processing plant wastewater with precipitation using different coagulants, such as sepiolite, zeolite, and pumice in dosages of 0.5–8 g/500 mL and mixed in 20 wt % with commercial epoxy resin. The effects of marble, coagulant type and dosage on the physicomechanical and thermal properties were investigated. The incorporation of marble processing waste particles increases the 10% decomposition temperature of pure epoxy by 5–50°C. Surface hardness, tensile strength, percentage elongation, and stress at maximum load of the composites were higher than those of pure resin, too. The composites reinforced with marble processing waste-pumice showed about 10% increase in elastic modulus, whereas the composite reinforced with marble processing waste-sepiolite or zeolite showed about 76.67–143.33% increase in elastic modulus over the pure epoxy matrix. Scanning electron microscopy (SEM) was used for characterization of surface and cross sections of the composites to verify the results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Application of linear programming in production planning at marble processing plants

Most companies in the marble sector are planning and programming their production using portfolio of orders, their experiences, and practical forecasts. Renta? Marble plant is chosen to carry out this study, where all production steps have been observed and recorded for a year. The authors used production capacity and loss reports, as well as software Lingo 8.0 in their researches. The scope of application for the linear programming method is defined. Software Lingo 8.0 is run for the best, worst, and average production conditions with respective assumptions made. The efficiency of products produced at the plant to obtain the highest revenue with a reasonable rate of loss is evaluated. The marketing policies for companies are developed.

Determination of discontinuities in marble blocks via a nondestructive ultrasonic technique

Miners working in the marble industry have always been interested in identifying structural weaknesses in marble blocks before they are transported to marble processing plants. To achieve this difficult task, several simple methods have been developed among miners but observation-based methods do not consistently provide satisfactory results. A nondestructive method developed for testing concrete could be used for this purpose. In this study, this simple method based on differences in ultrasonic wave propagation in different materials was presented, and the test results performed both in the laboratory and a marble quarry were discussed.

Geological and technical characterisation of Iscehisar (Afyon-Turkey) marble deposits and the impact of marble waste on environmental pollution

Turkey, due to its location in the Alpine-Himalayan belt, has numerous marble deposits. More than 250 marble types with different colours and patterns have been produced from these deposits and one hundred of these are well known around the world. One such well-known marble type is Afyon-Iscehisar. Afyon-Iscehisar is Palaeozoic in age and has been quarried since the era of the Roman empire. The Afyon region is known as one of the most important marble production and processing centres in Turkey. The Afyon province, which possesses 3.5% of exploitable marble reserves (3,872,000,000 tonne) in Turkey, yields 9% of the total marble block production. The 409 marble processing plants in Afyon produce 19% of the total slab in Turkey. As a result of marble production activities, approximately 340,000 tonne of marble waste has accumulated in the area. While some of these unshaped marble blocks are re-used and returned to the economy, the majority are discarded. There are two waste marble storage fields located in the Afyon-Iscehisar region. All of the solid and fine-grained marble waste is stored in waste marble storage fields in Susuz Boğazı and in the nearby Iscehisar marble quarries. The ecological effects of the marble waste, which were once discharged everywhere and exhibited visual pollution, has now been reduced to a minimal level.

The Application of Critical Path Method (CPM) in Workflow Schema of Marble Processing Plants

The critical path method (CPM) is a widely applied technique in large-scale industrial project planning and control. Based on a detailed review of the current literature, no references have been found referring to the use of the CPM in marble processing plants and other industrial mineral plants. In this regard, this study proposes a new application area of CPM and suggests the implementation details of mineral processing workflows with particular emphasis on marble production facilities. In the study, the CPM is applied to marble processing plants for selecting an applicable production process and for determining the workflow schema in order to optimize the cost of operation and to effectively manage time. As a consequence of this analysis, a new production plan is proposed for medium-scale marble processing plants. A suitable marble processing plant has been built and taken into operation in accordance with the proposed plant plan. It has been observed that this plant has a higher production rate at a preferable capacity when compared to three other plants studied as a part of this research.

Physico-chemical treatment of marble processing wastewater and the recycling of its sludge

In the first part of this study, the treatability of marble processing wastewater by the coagulation-flocculation process was investigated. Optimum coagulant-flocculant doses for turbidity removal in wastewater from the cutting, faience and equalization processes were determined as 500, 200 and 500 ppm of Al2(SO4)3; 300, 500 and 300 ppm of FeCl3 and 600, 400 and 200 ppm of Agrofloc 100 (AGRON Water Treatment Technologies and Chemical Marketing Industry and Trade Limited Company, Izmir, Turkey), respectively. It was found that the removal of total solids from cutting and equalization process wastewaters was highest for the 100 ppm dosage of all chemicals used. The amount of total solids removed from faience process wastewater by Agrofloc 100 was higher than that removed by the other chemicals used. The removals of suspended solids from cutting, faience and equalization process wastewaters were similar to each other for each of the chemicals. The pH values after treatment by Agrofloc 100 were higher than the values determined after treatment by other chemicals for all process wastewater. Electrical conductivity values, however, were lower for Agrofloc 100 than for the others. Settled sludge volume experiments showed that settled sludge volumes decreased with time. The results of the quiescent settling experiment showed that the settling type could be termed flocculent settling. In the second part of the study, the usage of waste sludge from marble processing as an additive material in cement was investigated. The waste sludge originated from the wastewaters of different steps of the marble processing plant. Waste sludge was replaced with cement at various percentages by weight to prepare the mixtures of mortar. The specimens poured into the moulds were held for 24 h, removed from the moulds and held again for 28 days in lime-saturated water at 23 degrees C. Compressive and flexural strengths were evaluated with respect to percentages of waste sludge replaced with cement. The maximum compressive and flexural strengths were observed for specimens containing a 6% waste sludge when compared with control and it was also found that waste sludge up to 9% could effectively be used as an additive material in cement.

Crossflow microfiltration of marble processing wastewaters

The wastewaters generated during the marble processing (cutting and grinding operations), the average flow rates of which are ca. 15 m 3/h for a plant producing 45 m 2 of polished marble/h, contain a high load of particulate matter. Furthermore, crushed stone operations sometimes use flotation agents, such as organic amines, fatty acids, and pine oils, in order to remove impurities from the marble. Therefore, the marble processing wastewaters should not be disposed directly into the environment without a suitable treatment in order to prevent negative impacts and comply with the national legislations currently in force. On the other hand, bearing in mind the severe water shortage in Mediterranean countries, which are intensive producers of carbonaceous rock and stone, it would be of utmost importance to recover and reuse the processing wastewaters generated in these plants. In this work, the treatment of marble processing wastewaters by microfiltration (MF) was investigated. Wastewaters from a marble processing plant located in Pero Pinheiro, Portugal, were characterised in terms of pH, conductivity, total solids (TS), and total suspended solids (TSS). A Micro Carbosep 60 module equipped with a mono-tubular mineral MF membrane, Carbosep M45 (nominal pore size = 0.45 μm, ID = 6 mm, L = 0.60 m), was tested at ambient temperature, natural effluent pH, a broad range of transmembrane pressures and crossflow velocities, and up to a 9-fold concentration. MF eliminated the suspended matter from marble wastewaters, allowing the treated water to be recycled into the process, whereas the concentrated stream (rich in particulate matter) can be used elsewhere, e.g. in the ceramic industry. The results from this work clearly show that MF is an efficient and ecologically suited environmental technology for decontamination and recycling of the wastewaters generated by marble processing plants, besides the environmental pollution abatement involved.