مقاومت و دوام مصالح باطله سنگ‌آهن تثبيت شده با سيمان به عنوان مصالح اساس: مورد مطالعاتي معدن گل‌گهر

Strength and Durability of Iron Ore Tailing Materials Stabilized using Portland Cement as Base Materials: A Case Study Of Golgohar Mine

ﺑﻪﻣﻨﻈﻮر ﮐﺎﻫﺶ ﺗﺄﺛﯿﺮات زﯾﺴﺖﻣﺤﯿﻄﯽ ﻧﺎﺷﯽ از ﺑﺎﻃﻠﮥ ﺳﻨﮓآﻫﻦ و ﻫﻤﭽﻨﯿﻦ ﮐﺎﻫﺶ اﺳﺘﻔﺎده از ﻣﺼﺎﻟﺢ ﺳﻨﮕﺪاﻧﻪاي ﻃﺒﯿﻌﯽ، ﻣﯽﺗﻮان ﭘﺲ از ﺗﺜﺒﯿﺖ اﯾﻦ ﻣﺼﺎﻟﺢ ﺑﺎ اﻓﺰودﻧﯽﻫﺎي ﺷﯿﻤﯿﺎﯾﯽ، از اﯾﻦ ﻣﺼﺎﻟﺢ ﺑﻪ ﻋﻨﻮان ﻣﺼﺎﻟﺢ روﺳﺎزي اﺳﺘﻔﺎده ﻧﻤﻮد. در اﯾﻦ ﺗﺤﻘﯿﻖ، اﻣﮑﺎن اﺳﺘﻔﺎده از ﺑﺎﻃﻠﮥ ﺳﻨﮓآﻫﻦ ﻣﻌﺪن ﮔﻞﮔﻬﺮ ﺳﯿﺮﺟﺎن ﺗﺜﺒﯿﺖ ﺷﺪه ﺑﺎ 6 ،4 و 8 درﺻﺪ ﺳﯿﻤﺎن ﺑﻪﻋﻨﻮان ﻣﺼﺎﻟﺢ اﺳﺎس، ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺑﺮاي اﯾﻦ ﻣﻨﻈﻮر، آزﻣﺎﯾﺶﻫﺎي ﺗﺮاﮐﻢ ﭘﺮوﮐﺘﻮر اﺻﻼح ﺷﺪه، ﻣﻘﺎوﻣﺖ ﻓﺸﺎري ﺗﮏﻣﺤﻮري و آزﻣﺎﯾﺶ ذوب - ﯾﺨﺒﻨﺪان روي ﺗﺮﮐﯿﺐﻫﺎي ﻣﺨﺘﻠﻒ ﺑﺎﻃﻠﻪ ﺳﻨﮓآﻫﻦ و ﺳﯿﻤﺎن اﻧﺠﺎم ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺶ ﺗﺮاﮐﻢ ﻧﺸﺎن داد ﮐﻪ اﻓﺰاﯾﺶ ﺳﯿﻤﺎن ﺑﺎﻋﺚ اﻓﺰاﯾﺶ درﺻﺪ رﻃﻮﺑﺖ ﺑﻬﯿﻨﻪ و ﮐﺎﻫﺶ ﺣﺪاﮐﺜﺮ ﭼﮕﺎﻟﯽ ﺧﺸﮏ ﻣﯽﺷﻮد. ﺳﭙﺲ، ﻧﻤﻮﻧﻪﻫﺎي ﻣﺮﺑﻮط ﺑﻪ ﻣﻘﺎوﻣﺖ ﻓﺸﺎري ﺗﮏﻣﺤﻮري ﺑﺎ 6 ،4 و 8 درﺻﺪ ﺳﯿﻤﺎن و رﻃﻮﺑﺖ ﺳﻤﺖ ﺧﺸﮏ، ﺑﻬﯿﻨﻪ و ﺳﻤﺖ ﻣﺮﻃﻮب، در ﺳﻪ زﻣﺎن ﻋﻤﻞآوري 28 ،7 و 56 روزه ﺳﺎﺧﺘﻪ ﺷﺪﻧﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ﻣﯿﺰان ﺳﯿﻤﺎن از 4% ﺑﻪ 8%، ﺑﺮاي ﮐﻠﯿﮥ زﻣﺎنﻫﺎي ﻋﻤﻞآوري، ﻣﻘﺎوﻣﺖ ﻓﺸﺎري ﺑﯿﻦ 1/45 ﺗﺎ 2/15 ﺑﺮاﺑﺮ اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ اﺳﺖ. ﻫﻤﭽﻨﯿﻦ، ﻣﻘﺎوﻣﺖ در زﻣﺎن ﻋﻤﻞآوري 28 روزه و 56 روزه ﺑﻪ ﺗﺮﺗﯿﺐ در ﺣﺪود 1/73 ﺑﺮاﺑﺮ و 2/34 ﺑﺮاﺑﺮ ﻣﻘﺎوﻣﺖ 7 روزه ﻣﯽﺑﺎﺷﺪ. ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺶ دوام در ﺑﺮاﺑﺮ ﭼﺮﺧﻪﻫﺎي ذوب و ﯾﺨﺒﻨﺪان ﻧﺸﺎن داد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ درﺻﺪ ﺳﯿﻤﺎن، دوام ﻣﺼﺎﻟﺢ ﺗﺜﺒﯿﺖ ﺷﺪه اﻓﺰاﯾﺶ ﻣﯽﯾﺎﺑﺪ، ﺑﻪ ﮔﻮﻧﻪاي ﮐﻪ در ﻧﻤﻮﻧﻪﻫﺎي ﺑﺎ درﺻﺪ ﺳﯿﻤﺎن ﺑﯿﺸﺘﺮ، ﮐﻤﺘﺮﯾﻦ درﺻﺪ اﻓﺖ وزﻧﯽ و ﮐﺎﻫﺶ ﺣﺠﻢ ﻣﺸﺎﻫﺪه ﻣﯽﺷﻮد. در ﻧﻬﺎﯾﺖ، ﻣﺸﺨﺺ ﮔﺮدﯾﺪ ﮐﻪ ﺑﺎﻃﻠﻪ ﺳﻨﮓآﻫﻦ ﺗﺜﺒﯿﺖ ﺷﺪه ﺑﺎ ﺣﺪاﻗﻞ 4% ﺳﯿﻤﺎن، ﻣﻌﯿﺎرﻫﺎي ﻣﻘﺎوﻣﺘﯽ ﻻزم ﺑﺮاي ﺑﻪﮐﺎرﮔﯿﺮي در ﻻﯾﮥ اﺳﺎس را ﻓﺮاﻫﻢ ﻣﯽﮐﻨﺪ.

In order to mitigate the environmental impact of iron ore tailing (IOT) and also to reduce the use of natural aggregates, these materials can be used as road materials after stabilization with chemical additives. In this research, the feasibility of using Golgohar IOT, stabilized with 4, 6 and 8% of Portland cement as road base materials, has been investigated. To this end, modified Proctor compaction test, unconfined compressive strength (UCS) test and durability against freezing and thawing (F-T) cycles test were conducted on IOT samples stabilized with different percentages of Portland cement. Results of compaction testing on the samples showed that increasing the percentage of cement increases the optimum moisture content (OMC) and decreases the maximum dry density (MDD). In the next stage, IOT were stabilized using 4, 6 and 8% of Portland cement and UCS samples were fabricated with three different compaction moistures (dry side, optimum moisture content and wet side) and cured for 7, 28 and 56 days. The results showed that with increasing the percentage of cement from 4 to 8% for all curing times, the UCS increased between 1.45 to 2.15 times. Also, the 28-day UCS and 56-day UCS are about 1.73 times and 2.34 times the 7-day UCS, respectively. It was also found that the UCS increases with decreasing moisture content. The results of durability tests against (F-T) cycles on the samples showed that with increasing the percentage of cement, the durability of stabilized materials increases, so that in samples with higher percentage of cement, the lowest percentage of weight loss and volume reduction is observed. Finally, it was found that IOT stabilized with at least 4% of Portland cement provides the necessary strength and durability criteria for use as stabilized base layer.