Geri dönüşüm suyunun flotasyona etkisi
The effect of the recycled water on flotation
Yazar: ÇAĞLA DENİZ KOYUTÜRK
Danışman: PROF. DR. GÜLAY BULUT
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Cevher Hazırlama Mühendisliği Ana Bilim Dalı / Cevher Hazırlama Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Maden Mühendisliği ve Madencilik = Mining Engineering and Mining

Özet:
Bakır mineralleri, özgül ağırlıklarına ve fiziko-kimyasal özelliklerine bağlı olarak diğer minerallerden zenginleştirilebilir. Flotasyon bakır madenciliği endüstrisinde özellikle sülfürlü mineraller için en yaygın olarak kullanılan zenginleştirme yöntemidir.
Su hayatın her alanında olduğu gibi madencilik ve mineral işlemede oldukça önemli bir konudur ve madencilik sektöründe büyük miktarda su tüketimi gerçekleşmektedir. Flotasyon işleminde kullanılan suyun içeriğindeki kimyasal bileşenler flotasyon işlemine doğrudan etki etmektedir ve flotasyon sürecinde kullanılan reaktiflerin miktarını ve türünü de değiştirebilir.
Bu tezin başlıca amacı geri dönüşüm sularının flotasyon üzerindeki etkisinin incelenmesidir. Deneylerde geri dönüşüm suyunun flotasyona etkisi Murgul Çakmakkaya numunesi ve farklı su numuneleri ile çalışılarak araştırılmıştır. Sarıyer bölgesi şehir şebeke suyu, tesis yaz ve kış suları, laboratuvar ortamında oluşturulmuş geridönüşüm suları, deniz suyu ve laboratuvar ortamında suni olarak üretilmiş sular ile flotasyon yapılarak deney sonuçları karşılaştırılmıştır. Çalışma sonunda tesis kış geri dönüşüm suyu ile %21 Cu içeren konsantre en yüksek içerikle elde edilmiştir. Laboratuvar ortamında üretilen geri dönüşüm suları ile yapılan deneylerde içerik artarken, verim azalmaktadır. Suların çok tekrarlı kullanımına bağlı olarak içerisindeki sülfat, kalsiyum ve magnezyum gibi iyonların arttığı belirlenmiştir. Kış tesis suyunda bu iyonların konsantrasyonları en yüksek değerine ulaşmaktadır. Sülfatın ve kalsiyumun suni olarak hazırlandığı sular ile yapılan deneylerde özellikle sülfatın flotasyon verimlerini olumsuz yönde etkilediği belirlenmiştir. İyon konsantrasyonu çok yüksek olan deniz suyuyla yapılan deneylerde çok düşük içerik ve verimlerde konsantre elde edilmiştir. Bunun sebebi deniz suyu içerisinde geri dönüşüm sularında olduğu gibi yeterli miktarda reaktif olmaması şeklinde açıklanabilir. Geri dönüşüm suyuyla yapılan çalışmaların daha detaylandırılması ve tesis çapındaki incelemelerin arttırılması gerekmektedir.

Abstract:
Copper, because of its features, is an important metal in many industries today. Pure copper has a reddish brown color. Many properties of copper, which has a unique color, vary according to its purity and source. For example; copper with a high purity ratio is more ductile and highlights the processing characteristics of such copper. The melting temperature of copper is low and easily formable metal. Copper has an important role in welding, metallurgy and bronze production. The most important properties of copper are high electrical and thermal conductivity, resistance to abrasion and the ability to be hit and beat. In addition, the variety of alloys are used in the industry for various purposes. There are many minerals in the earth's crust, and some of these minerals are more common in nature. Copper ores are very rare in nature, mostly in the form of sulfuric minerals, oxides and complex minerals. Copper ores can be examined in two main groups as sulphide and oxides in nature. Chalcopyrite is the most important and most produced copper mineral. Chalcopyrite is usually found with pyrite, pyrrhotite, sphalerite, galena and fahlerz. The most common sulfurous copper ore in nature is chalcopyrite. n our country, copper reserves are concentrated in Eastern Black Sea and Southeastern Anatolia. Our copper deposits are classified as porphyry deposits, massive sulphide deposits and hydrothermal veins and contact metasomatic deposits. The amount of hydrotermal and contact metasomatic deposits is quite high but they are not rich in reserve. Porphyry deposits are not in the level of reserve and grade. Besides, massive sulphide deposits are very important in terms of copper mining in our country.
Copper minerals can be enriched from other minerals based on their specific gravity and physico-chemical properties. Methods of enrichment of copper ores include flotation, leaching and gravity. Because the chemical and physicochemical methods are not economically viable, copper ores are pre-enriched by physical methods, sometimes before the last enrichment. After pre-enrichment, a rather large size residue is discarded and the obtained coarse concentrate is finally enriched by grinding into the required liberalization size in the application of flotation. In pre-enrichment, separation is carried out using magnetic sensitivity and specific gravity differences. Enrichment by leaching method is called the solution of the precious metals based on the chemical dissolution differences and then the solution is obtained from the solution. In leaching of sulfuric and oxidized ores, heap, in situ, tank, mixing, pressure leaching methods are used.
Flotation is the most common enrichment method in the copper mining industry especially for sulfur minerals. Flotation is an important, versatile and selective separation method used to separate minerals and utilize the differences in physico-chemical surface properties of the minerals in the ore. It is known that enrichment process is carried out by flotation method of many minerals in mineral processing industry. Since the beginning of the flotation, different minerals have been processed and flotation behaviors have been investigated. Flotation of complex sulphide ores, the basis of copper, lead and zinc metals, has been the most studied group by researchers. Generally, anionic collectors (xanthates, dithyphosphates and mercaptans), polyglycols and alcohols are used as foams for the enrichment of sulphide minerals by flotation. In case sulfur free minerals are released in small size, together with gangue minerals in a very large size, firstly by rough flotation, the removal of gangue minerals is carried out and the obtained coarse concentrate is brought to smaller dimensions by grinding process and the sulfur minerals are separated by selective flotation. In the case of large-scale liberalization between the sulphide minerals and the pitcher, batch flotation provides an advantage over selective flotation.
Water is a very important issue in mining and mineral processing as it is in every area of life, and a large amount of water is consumed in the mining sector. Increased water demand and lack of fresh water lead to the recycling of water and the availability of new water resources. Water reuse has gained importance in recent years within the framework of sustainability research and the role of mining companies. Many mineral processing processes, such as grinding, flotation, heavy media separation, gravity enrichment and hydrometallurgical processes, use large amounts of water. Recycle water may include some residual reagents and their oxidation products, metallic ions, alkaline earth metal ions. Closed water circuits in flotation plants cause high electrolyte concentration in process water
The use of recycled water in flotation has a significant impact on selectivity and recovery. Most flotation plants perform at least some reuse and recycling. In modern mines, all available waters are recycled more than any other industry. In most cases, water quality has been shown to influence flotation performance, and this interaction remains under investigation. Research has shown that increasing the use of recycling water in flotation often has negative effects on mineral separation. When recycle water is used, inorganic (suspended matter, metals, calcium, magnesium, sodium, sulfite, etc.) and organic dissolved compounds accumulate and these components are those that alter the chemistry of the system and affect flotation performance. The use of recycled water or poor quality water can cause some effects on the process water quality due to the accumulation of certain chemical species. The chemical components in the water used in the flotation process directly affect the flotation process and can also change the amount and type of reagents used in the flotation process. Eh-pH varying in water, salt concentration and ionic hardness, suspended substances and dissolved substances, the amount of dissolved oxygen, organic and microbiological activities cause various effects in flotation. In separation of the flotation process; the reagent is directly influenced by the relationship between concentration and pH, so pH plays a very important role in flotation.
The most suitable medium for the flotation method is the alkaline environment. Because a lot of collectors are stable in the alkaline environment. In some studies, Na+ and Mg+ effects were investigated and it was observed that salt concentration changed flotation performance. Separation of minerals depends on the different surface properties of the flotation. Because the mineral changes the surface chemistry, the dissolved solids have a large negative impact on flotation.
In order to investigate the recycled water effects on flotation, some studices were conducted by researchers. In some studies conducted with tap water, recycling water, waste dam water, underground mineral water and sea water, the highest ion concentrations were determined as calcium and sulfate. According to this study, it has been found that high ion concentration negatively affects flotation recovery as seawater. However, certain amounts of ion concentrations and residual reagents have improved flotation performance as recycling water and waste dam water. Another study examined the effect of recycling water on oxidized copper ore. Recycling water has a detrimental effect on malachite flotation due to bicarbonate ions. At very low concentrations, bicarbonate ions disrupt the flotation of copper. It also causes the drift of minerals and increases the consumption of reagents.
The aim of this thesis is to examine the effect of recycling water on flotation. The effects of recycling water on flotation were investigated with Murgul Çakmakkaya sample. Different water types used for flotation experiment and these results compared with each other. As a result of this study, the concentrate of the recycling water of facility during winter flotation experiment contain the highest amount of the Cu with % 21. While the content of concentration increases, the yield of the concentration decreases by the overused recycling water. By depending on the over usage of the recycling water, the ions of the sulfate, calcium, and magnesium increases. The concentration of these ions are the highest in the recycling water of facility during winter. The artificial water with sulfate has a bad influence on the the productivity of flotation process. The experiments performed with sea water that rich in ion concentration display very low rate content and yield. Because of the low quantity of reagent.