نشریه نمک
سال یکم شماره 2 (پاییز 1390)

Crude oil as the main row material in industries is one of the most strategic and valuable materials in the world. In one hand, after World Wars and the issues they caused for oil marketing, many of North American, European and Eastern Asian countries began to store crude oil till in emergency cases they can protect their economy and industries against probable damages. On the other hand, even in the absence of war and any international threat against Iran oil marketing it still facing its own challenges. In the low crude oil demand periods, there should be enough stores for storing crude oil to prevent any problem in producing and storing of it in the country. Since various methods such as aboveground tanks, floating, in-ground and underground oil storage has been experienced. Large storage capacity, high safety and low operational and maintenance costs of underground storage in comparison with the other methods have been caused to be more concerned in many countries. Underground crude oil storage methods including hard rock caverns, abandonment mines and salt caverns have been widely used. Choosing the appropriate storage method with respect to country conditions has positive political and economic consequences. In this study, technical, environmental, economical, defensive criteria effective on crude oil storing has been investigated, and also by taking advantages of internal and external expert’s viewpoints, the appropriate methods of underground storing has been prioritized. Due to effects of various criteria on choosing the suitable storage methods, application of Multi Criteria Decision Making (MCDM) methods would be important. In this study with application of Fuzzy Analytic Hierarchy Process (FAHP) and with respect to our country situations, the appropriate underground crude oil storage of methods has been prioritized.

The Kangan Formation with age of Early Triassic (Scythian) is one of the most important gas reservoir in southwest of Iran and Persian Gulf. This formation is mainly composed of carbonate, evaporite and shale facies. In this research, several sub-surface sections of the Kangan Formation in Fars sub-basin related to Zagros Basin were selected and studied for recognition and interpretation of anhydrite facies and its fabrics. In the studied area, the Kangan Formation unconfomably overlies the Dalan Formation (late Permian) and conformably underlies the Dashtak Formation (Middle- Late Triassic). Investigations of the Kangan Formation facies in the studied sections show that these facies were deposited in sabkha/tidal flat, lagoon, shoal/barrier and open marine environments that related to a ramp or epeiric carbonate platform. Petrographic studies of the cores and thin sections of the carbonate- evaporite deposits of the Kangan Formation indicate that anhydrite in this formation has a variety thicknesses and fabrics such as individual nodules, chicken-wire, enterolithic, lenticular, tabular/bladed, spheroid/fan, decussate, acicular/fibrous, mosaic and pore-filling cement. Investigation of these fabrics shows that the most of them were formed syndepotional and/or early diagenetic.

In this project 41 sample salt were taken from all active salt mines and table salt factories in Garmsar region. The amount of Pb and Cd in samples were determined and investigated according to appropriate national standard of Iran and Codex by inductively coupled plasma optical emission spectrometry (ICP-OES) method, the amount of As were determined and investigated according to appropriate international standard of AOAC by atomic absorption spectrophotometry(AAS) after generation of Arsenic hydride and the amount of Hg were determined and investigated according to appropriate British national standard(BS7319) by cold vapour atomic absorption spectrometric method. In accordance with national standard of Iran and Codex standard the allowed maximum limit of Pb is respectively 1ppm and 2ppm, of Cd is respectively 0.2pmm and 0.5ppm, of As is 0.5 ppm and of Hg is respectively 0.05ppm and 0.1ppm. The results showed that the amount of Pb, Cd and Hg in all of the studied samples was less than detection limits of the appropriate used methods and was bellow the allowed maximum limits. The amount of As in many of samples was less than detection limits of the used method (50ppb) and of other samples was in range of 50 ppb to 130 ppb and lower than the allowed maximum limit. Fortunately the results showed that the quality of salts of mines in Garmsar in case of heavy metals is well accordance with national standard. So if the results of analysis of factory's products are acceptable in according to standards, the quality control of mines for those elements will be unnecessary.

Garmsar is western city of Semnan province, which is equivalent to 9,233 square kilometer area from the north, Damavand and Firuzkuh, Varamin in the West, the East of Semnan and South Central Desert and finally limited to the Naeen city in Isfahan province. Masses of evaporating are beautiful and remarkable structural. The masses have wide exposure in the West, North West and North of city. The mother layer masses of evaporating are evaporating part of Lower Red Formation and Kond Formation at the time Eocene - Oligocene and a platform in a shallow sea margin are formed. Also, in the Lower Red Formation, multiple masses of igneous sub volcanic have been penetrated. In this study has tried that found time and place kind of relationship between the formations of Lower Red Formations with magmatism occurred.

Studying soil’s problems in arid and semi-arid regions is of supreme importance in preserving production sources (water and soil) and their constant utilization. Particular ecological conditions of such regions, especially Iran, bring about sodium and salty soils. Salty soils of Iran include considerable amounts of soluble salts which have great influence on properties of the soil. Precise identification and extending different types of salty soils have a significant role nutritional programming of a country. From economical aspects, agric activities and cultivation of foodstuff in such regions require a full-scale recognition of soil and a set of complex arrangements which are totally different from exploiting methods of water and soil sources. It is evident that obtaining desirable results from amendment and productivity programs of soil and investment of agriculture developments in salty soils is conditioned to having precise information about the properties of such soils. So this article reviews the properties of soil in arid and semi-arid regions, having a view on studies done in this field and also classifies salty soils to compare them accurately.

The sedimentary geochemistry studies carried out on the Miocene evaporite deposits of the M1 member of Upper Red Formation for identifying the origin of the Melheh mine evaporates have been deposited in the Great Kavir Basin to the South Semnan city. The mineralogical examination results represent the Halite, Gypsum, Polyhalite, Langbinite and Carnalite in minerals assemblages. Among them, Polyhalite, Langbinite and Carnalite are placed outside the primary halite grains. The latter minerals group forms when the enough amount of K and few Mg are present. Layering of the evaporite deposits shows the depositional textures such as cumulate, chevron and cornet in halite and sylvite is strong evidence to their depositional setting which connected to the sea waters. Furthermore, the Br geochemistry as trace element in the halite and sylvite crystals double checked the origin of Melheh mine deposits. The Maximum Br concentration in halite is 200 ppm. The primary depositional textures like layering associated with shallow marine facies support the idea that they may have formed under marine conditions. According to the observations and geochemical data they have been deposited in a shallow Great Kavir Basin and possibly the evaporative brine could be originated from the Qom sea waters.

Salt is one of the most complex rocks from geomechanical behavior aspect that shows large deformation even at very small deviatoric stresses. Saltrock Time-dependent deformation behavior under constant loads is another important issue that plays a significant rule in underground space design engineering in saltrock. Physical parameters like temperature, stress level, stress difference, moisture and etc. have influence on salt characteristics. In this paper, the most effective variables on design of underground spaces in salt rock will be discussed. Then, experimental results which have been obtained by other researchers will be investigated for better understanding of the effects physical parameters on saltrock behavior.

The effect of Na2O، CaO and BaO which are available in a type of borosilicate opal glasses were examined in water and steam leaching. The results show ideal properties are dependent to the limited ratio of Na2O/ BaO + CaO. The batch for borosilicate opal glass mostly contains components that are added in very small amounts، e. g.، Sodium Meta phosphate، Calcium Carbonate، Barium Carbonate، which must be weighed very carefully. This investigation is disclosed new compositions of borosilicate glasses، opacified with P2O5 which have high chemical durability and low thermal expansion coefficient، with general composition SiO2 73. 0، B2O3 11. 70، Al2O3 3. 30، P2O5 1. 30، Na2O (9. 6-(X+Y))، CaO (X=0. 1-050) and BaO (Y=4. 5-2. 9) wt%.