jamesp
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Post by jamesp on Feb 24, 2019 7:30:15 GMT -5
I successfully polished rocks in a rotary using AO 500 and AO 14,000 polish using pulverized ag lime as the slurry 4 years ago before acquiring a vibratory tumbler. No media or smalls were used since the slurry was fairly thick and protective even though the rocks were all on the large side. This particular AG lime has a super low silica-crystalline quartz content at only .1 to .2 percent to prevent scratches. Never tried it in a vibe but it should work fine due to very low sand content. It is alkaline and best handled with gloves. Please excuse the Georgia accent: This product was chosen because it had the lowest quartz content of all powered clays and limestones I could find on the market. I believe I paid $8 for the 50 pound bag.  |
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Post by HankRocks on Feb 24, 2019 8:04:19 GMT -5
I successfully polished rocks in a rotary using AO 500 and AO 14,000 polish using pulverized ag lime as the slurry 4 years ago before acquiring a vibratory tumbler. No media or smalls were used since the slurry was fairly thick and protective even though the rocks were all on the large side. This particular AG lime has a super low silica-crystalline quartz content at only .1 to .2 percent to prevent scratches. Never tried it in a vibe but it should work fine due to very low sand content. It is alkaline and best handled with gloves. Please excuse the Georgia accent: This product was chosen because it had the lowest quartz content of all powered clays and limestones I could find on the market. I believe I paid $8 for the 50 pound bag. Like that polish slurry, may have to try it sometime. There's also that sound that well polished rocks make in the tumbler and when cleaning, it a distinct sound and it's music to my ears!! One question, What accent? Henry |
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Post by grumpybill on Feb 24, 2019 8:41:45 GMT -5
This thread piqued my interest, so I looked through my file of old MSDS and SDS sheets for hydrated lime (used in masonry mortar) and found this note on one of the sheets: The two ranges were given as: 0 - 0.1% and 0.1 - 1%. hydrated lime MSDS.pdf |
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jamesp
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Post by jamesp on Feb 24, 2019 8:43:52 GMT -5
Lol HankRocks, accent alive and well(to them thar foreigner's ears). I looked at 50 pound bags of bentonite, ag lime, ball field marking lime, kaolin, etc. Quartz percentages ranging from 1 to 5%. This had crazy low quartz at .1 to .2%. This particular lime was mined in Canada and apparently the source calcium carbonate is darn near quartz free. The local feed store had it in stock. But it is almost as hot as Portland so you should consider using gloves. |
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jamesp
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Post by jamesp on Feb 24, 2019 8:56:46 GMT -5
This thread piqued my interest, so I looked through my file of old MSDS and SDS sheets for hydrated lime (used in masonry mortar) and found this note on one of the sheets: The two ranges were given as: 0 - 0.1% and 0.1 - 1%. hydrated lime MSDS.pdfExcellent. Those are low quartz percentages for sure. They reduce the quartz probably because it is a carcinogen and you concrete guys are vulnerable to breathing it. Lime clays(basically the same as pulverized lime) are not felspar based so they are composed of rounder particles instead of flat colloidal plate particles. So lime settles in water faster. Not a big issue but it is better not good to let your barrel sit for a long time (longer than 5 minutes) or you will get a concretion in the bottom of your barrel. Not good for power outages. Here is a settlement test after an hour and note how clean the water is on top, where colloidal particles will stay in suspension for days doing same test.  Granite, basalt and lime clays:  |
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Post by grumpybill on Feb 24, 2019 11:46:49 GMT -5
They reduce the quartz probably because it is a carcinogen and you concrete guys are vulnerable to breathing it.
I personally think the fear of silicosis is overblown. I worked in masonry construction for over 45 years and to this day know of only one person ever diagnosed with silicosis...which was later found to be an autoimmune disease totally unrelated to silica. I was often the sawman on jobs where the material needed to be sawed dry. I've also spent a lot of time dry-grinding old mortar joints for repointing. I've dumped more than a few bags of white sand (pure silica) into mortar mixers. I seldom wore a dust mask. For days at a time I couldn't be seen through the cloud of dust. Nostrils caked full of dried dust. Eyelids glued shut when I'd wake up the next morning. |
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Post by parfive on Feb 24, 2019 14:10:05 GMT -5
I worked in masonry construction for over 45 years and to this day know of only one person ever diagnosed with silicosis... Kinda odd, really, how so many masons and laborers seem to avoid the lung diseases that nail coal miners. I grew up in an Italian section of town crawling with brick and stone masons and never saw it affect my friends’ fathers or grandfathers or uncles. Genes, the grappa, workin’ in the fresh air, who knows? forum.rocktumblinghobby.com/thread/85788/clean-coal-quartz |
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Deleted
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Post by Deleted on Feb 24, 2019 15:33:11 GMT -5
The following is not intended to discourage anyone from taking precautions.
I personally think the fear of silicosis is overblown. I worked in masonry construction for over 45 years and to this day know of only one person ever diagnosed with silicosis...which was later found to be an autoimmune disease totally unrelated to silica. I was often the sawman on jobs where the material needed to be sawed dry. I've also spent a lot of time dry-grinding old mortar joints for repointing. I've dumped more than a few bags of white sand (pure silica) into mortar mixers. I seldom wore a dust mask. For days at a time I couldn't be seen through the cloud of dust. Nostrils caked full of dried dust. Eyelids glued shut when I'd wake up the next morning. I agree with you. Taking precautions isn't going to hurt anyone, but I personally doubt that such will be preventing silicosis among most hobbyists who don't have existing health problems. There are other factors at work which may contribute- a good percentage of those miners also smoke (that's also tobacco country, and many grow their own), there are different types of particles produced by blasting than from grinding, miners in the past have not had access to good health care, there are different things in mining dusts other than just silica, etc. Silica itself is benign - it doesn't "cause" anything. We all breathe in some of it in everyday life, eat off it, swallow it in our foods and medicines, drink it in our water. It is in the air (windborne dust) as well as in all kinds of work environments. The problem only comes when the dust consists sharp, angular shards (of whatever material) that are of a certain size that can get lodged in the lungs, cannot be expelled or dissolved and cause scarring. Silicosis is the same problem as in asbestosis, which used to be the diagnosis among coal miners. Bad conditions in badly run underground mines where fresh blasting shards/dust can hang in the air and cling to (and eventually drop off) ceilings and walls are not equivalent to most other exposure. If it were, then silicosis would be a much bigger problem. |
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jamesp
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Post by jamesp on Feb 24, 2019 16:27:09 GMT -5
They reduce the quartz probably because it is a carcinogen and you concrete guys are vulnerable to breathing it.
I personally think the fear of silicosis is overblown. I worked in masonry construction for over 45 years and to this day know of only one person ever diagnosed with silicosis...which was later found to be an autoimmune disease totally unrelated to silica. I was often the sawman on jobs where the material needed to be sawed dry. I've also spent a lot of time dry-grinding old mortar joints for repointing. I've dumped more than a few bags of white sand (pure silica) into mortar mixers. I seldom wore a dust mask. For days at a time I couldn't be seen through the cloud of dust. Nostrils caked full of dried dust. Eyelids glued shut when I'd wake up the next morning. Seems a bit over dramatic Bill. When plowing or mowing in dry soil there is much silica in the dust. Or road dust when living on a gravel road. Silica is the most common mineral... |
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Post by grumpybill on Feb 24, 2019 16:44:37 GMT -5
Seems a bit over dramatic Bill... Yet, how many times a week do we see warnings to always wear a dust mask - a full respirator, even! - when cutting stones? To me, that's being over dramatic. As you wrote: silica dust is everywhere. How many people have silicosis? |
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Post by toiv0 on Feb 24, 2019 16:51:16 GMT -5
I knew one person who had silicosis, he had worked in the Bentonite clay mines in SD.
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pizzano
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Post by pizzano on Feb 24, 2019 18:03:36 GMT -5
I successfully polished rocks in a rotary using AO 500 and AO 14,000 polish using pulverized ag lime as the slurry 4 years ago before acquiring a vibratory tumbler. No media or smalls were used since the slurry was fairly thick and protective even though the rocks were all on the large side. This particular AG lime has a super low silica-crystalline quartz content at only .1 to .2 percent to prevent scratches. Never tried it in a vibe but it should work fine due to very low sand content. It is alkaline and best handled with gloves. Please excuse the Georgia accent: This product was chosen because it had the lowest quartz content of all powered clays and limestones I could find on the market. I believe I paid $8 for the 50 pound bag. We have a few lime quarry's out here that mainly mine for the purpose of cement manufacturing.......I've hounded at couple places.....maybe I'll snag some "powder" the next time out there.......sounds like a decent slurry helper. |
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jamesp
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Post by jamesp on Feb 25, 2019 6:02:49 GMT -5
Looking at the size of AO 14,000 polish. 14,000 grit is 1 micron or about .00004 inches. There is 1000 microns in a millimeter. A blood cell is 5 microns across. For this reason clays and containing quartz and felspars could be risky to polish with because of their Mohs hardness. Could be risky or slow polishing process, not sure. The other reason I tried lime pizzano was because lime is basically calcium carbonate or calcite and is soft with a Mohs hardness of only 3. Alternative polishing slurries - Borax(Boric acid) is about Mohs 3 and sugar is soft and dissolves. All soft. |
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jamesp
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Post by jamesp on Feb 25, 2019 6:31:00 GMT -5
Seems a bit over dramatic Bill... Yet, how many times a week do we see warnings to always wear a dust mask - a full respirator, even! - when cutting stones? To me, that's being over dramatic. As you wrote: silica dust is everywhere. How many people have silicosis? Univ. of Georgia did a study on plant growth along granite gravel roads and found exceptional plant growth due to gravel dust from tires constantly grinding granite. Look at crushed granite and notice it has sharp edges when first spread on a gravel road; after a few years it looks like it was coarse tumbled w/rounded edges. So the dust. Granite dust is also sold as a soil amendment and is also full of silica particles. I did know an elderly lapidarian that died of lung issues at age 91. He could walk/work you into the dirt at age 89. He made and used dry grinding lapidary machines that made a lot of dust. He also smoked heavily. Not so sure if they knew the cause of his lung issues. Some simply have weak lungs. Hey, if I hit 91 like Bill Burke did I will be tickled pink. No doubt some minerals are poisonous. Not so sure about silica. Now they say talc powder causes cancer, namely those building a class action law suit. Who to trust ? |
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Post by vegasjames on Feb 25, 2019 6:49:50 GMT -5
They reduce the quartz probably because it is a carcinogen and you concrete guys are vulnerable to breathing it.
I personally think the fear of silicosis is overblown. I worked in masonry construction for over 45 years and to this day know of only one person ever diagnosed with silicosis...which was later found to be an autoimmune disease totally unrelated to silica. I was often the sawman on jobs where the material needed to be sawed dry. I've also spent a lot of time dry-grinding old mortar joints for repointing. I've dumped more than a few bags of white sand (pure silica) into mortar mixers. I seldom wore a dust mask. For days at a time I couldn't be seen through the cloud of dust. Nostrils caked full of dried dust. Eyelids glued shut when I'd wake up the next morning. I kind of agree with you.
First of all it takes very long term exposure to lead to this not only in long duration daily exposure but also years of that daily exposure. It is not like occasional exposure or short term exposure is going to be an issue.
And also it still would depend on the form of silica also.
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Post by vegasjames on Feb 25, 2019 6:58:18 GMT -5
Looking at the size of AO 14,000 polish. 14,000 grit is 1 micron or about .00004 inches. There is 1000 microns in a millimeter. A blood cell is 5 microns across. For this reason clays and containing quartz and felspars could be risky to polish with because of their Mohs hardness. Could be risky or slow polishing process, not sure. The other reason I tried lime pizzano was because lime is basically calcium carbonate or calcite and is soft with a Mohs hardness of only 3. Alternative polishing slurries - Borax(Boric acid) is about Mohs 3 and sugar is soft and dissolves. All soft. Actually lime is calcium oxide/hydroxide. It is made by heating of limestone (calcium carbonate) "burning off" the carbonate as carbon dioxide. Lime does rapidly absorb CO2 though reverting back to calcium carbonate. This is why lime has been long used as a CO2 scrubber in underwater breathing apparatuses and submarines.
I don't really tumble but this brings up a question I have heard people have, which is gas build up. Wouldn't a carbonate like calcium carbonate, which lime will eventually form back in to increase the risk of gas formation in the barrels?
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jamesp
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Post by jamesp on Feb 25, 2019 8:05:36 GMT -5
Looking at the size of AO 14,000 polish. 14,000 grit is 1 micron or about .00004 inches. There is 1000 microns in a millimeter. A blood cell is 5 microns across. For this reason clays and containing quartz and felspars could be risky to polish with because of their Mohs hardness. Could be risky or slow polishing process, not sure. The other reason I tried lime pizzano was because lime is basically calcium carbonate or calcite and is soft with a Mohs hardness of only 3. Alternative polishing slurries - Borax(Boric acid) is about Mohs 3 and sugar is soft and dissolves. All soft. Actually lime is calcium oxide/hydroxide. It is made by heating of limestone (calcium carbonate) "burning off" the carbonate as carbon dioxide. Lime does rapidly absorb CO2 though reverting back to calcium carbonate. This is why lime has been long used as a CO2 scrubber in underwater breathing apparatuses and submarines. I don't really tumble but this brings up a question I have heard people have, which is gas build up. Wouldn't a carbonate like calcium carbonate, which lime will eventually form back in to increase the risk of gas formation in the barrels?
Thanks for that clarification James. This may have been Ag lime. If I am not mistaken Ag lime is limestone(or marble) that was pulverized and never heated in a kiln. I distinctly remember using 2 different limes, I believe one was hydrated and the other was Ag lime with a brand name "High Calcium Limestone" mined in Ontario by Pestle Minerals and Ingredients. One of the two would burn my hands, you may know which one has the higher ph. My first thought was the classic vinegar/baking soda bomb, especially with Georgia ph 6.2 acid water. I never had an issue with gas. I do run slurry helpers for about 10 minutes and then open the barrel to check consistency. Maybe the 10 minute run did enough mixing to complete the ph reaction ? I only used the lime thickener in the alum ox 500 and alum ox polish steps, starting with fresh lime each step after clean out. The coral in the photo below has what seems to be a heavy limestone coating of which has been tumbled off without using abrasives because it is so soft. However these limestone? coated silicified corals came out of (ph 4.5 to 5.0) Florida tannic acid rivers perhaps neutralizing ? I figured the ph would cause gas but it never happened. This limestone? coated coral was my first experience tumbling with slurry. It had to be cleaned out every day for 2 to 3 days or it would get too thick. However it is loaded with sharp silica 'needles' and served well as an abrasive. No need to waste good abrasive removing this soft skin. Handling large chunks of coral would wear on your skin due to these imbedded silica needles in the limestone? skin. Guessing the silica needles are some sort of crystalized quartz shapes caused by dissolved diatoms in limestone. Some of the coral was 4 feet across and silicified solid so there was no shortage of dissolved silica.  Same coral before tumbling, dirty and stained but abrasive to fingers.   |
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Post by vegasjames on Feb 25, 2019 19:14:36 GMT -5
Yes, agricultural lime is crushed limestone or chalk and thus is calcium carbonate. I use common lime with a lot of my experiments. It is calcined limestone forming calcium oxide primarily used to make cement, but also in the processing of some foods like hominy.
If you have a USB microscope it would be cool to see the silica crystals under high magnification. That may also help tell you if they are from diatoms or not. Other possibility is silica replacement of the coral polyps when live can still be very sharp.
There could be something else preset that cold be buffering acids such as maybe phosphate buffers or something else. The gas build up would just be something to keep in mind since water pH varies from place to place and even the rocks can alter pH or the lichens that grow on a lot of them.
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kskid
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Post by kskid on Feb 25, 2019 23:32:29 GMT -5
Hey grumpybill, jamesp, and others - I was taught a slightly different angle regarding the silica dangers that helped me choose (or not) to use PPE. I was taught that the recommended protections for things like silica, asbestos, and mercury are seemingly out of proportion to the danger because once these items get into our body they literally never get out. The result is that every exposure, no matter how small, is cumulative over an entire lifetime. We can't possibly quantify the actual "dose received" due to the many circumstances of exposure you guys already mentioned. And there's no way to know what future exposures may be (i.e., a 9/11 type event, earthquake, moving onto a gravel road, etc). So the prudent course is to eliminate the known or predictable exposures. That context sometimes helps me choose to stop and put on a mask when I really would rather continue without one. And sometimes I'm willing to take my chances and don't. I'm only sharing this because I was helped by the information & thought I'd pass it along. I'm all about freedom to make personal choices.  |
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Post by vegasjames on Feb 26, 2019 1:02:22 GMT -5
Hey grumpybill , jamesp , and others - I was taught a slightly different angle regarding the silica dangers that helped me choose (or not) to use PPE. I was taught that the recommended protections for things like silica, asbestos, and mercury are seemingly out of proportion to the danger because once these items get into our body they literally never get out. The result is that every exposure, no matter how small, is cumulative over an entire lifetime. We can't possibly quantify the actual "dose received" due to the many circumstances of exposure you guys already mentioned. And there's no way to know what future exposures may be (i.e., a 9/11 type event, earthquake, moving onto a gravel road, etc). So the prudent course is to eliminate the known or predictable exposures. That context sometimes helps me choose to stop and put on a mask when I really would rather continue without one. And sometimes I'm willing to take my chances and don't. I'm only sharing this because I was helped by the information & thought I'd pass it along. I'm all about freedom to make personal choices. Again there are various forms of silica. For instance the body absorbs and utilizes silica in the form of orthosilicic acid. And the body does lose that silica over time, which is why we can develop diseases and conditions related to orthosilicic acid deficiencies including osteoporosis, osteoarthritis, emphysema, diverticulitis, wrinkles, etc.
In fact many fibers are full of silica, which is largely passed through the system.
Also keep in mind that there is silica that gets blown around in the air all the time, which means we inhale a lot of silica. Yet we do not all end up with silicosis because there are various factors involved such as much of the silica being trapped in the mucus produced by our mucus membranes then removed and also amount and term of exposure.
As for mercury, mercury that also has different forms only has a half life varying from 1 to nearly 90 days depending on factors such as the form of mercury.
Asbestos does appear to be more permanent in the body but contrary to popular belief it is not a cause of mesothelioma. According to research studies the mesothelioma is the result of the simian vacuole virus type 40 (SV40), which causes various cancers in humans. The asbestos was merely found to be a co-factor like how the hormones estrogen and progesterone do not cause cancer but can activate cancer viruses such as progesterone activation of human papilloma viruses linked to numerous cancers in humans including cervical, uterine, prostate, breast, nasopharyngeal, oropharynx, skin and other cancers.
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