# Gasketed filter press



## Harold_V (May 23, 2009)

Some time ago 4metals was discussing filter presses for use in refining. They're very handy for filtering large volume of solutions and can be a valuable asset. 

Filter presses vary considerably in how they deal with effluent. In cases where solutions are not particularly valuable, or where contamination of the effluent isn't an issue, it often is simply allowed to flow from each of the filter members, accumulating in a catch basin. An example of such an application might be one where properly treated waste solutions are separated from solid wastes, so the solution can be discharged to a sewer system, with the solids sent to hazardous waste disposal facilities. There is no affluent return circuit in the plates. That type of plate would not be satisfactory for the recovery of solutions of great value, or solutions that must be kept clean. 

In such a case, the design of the plates is of such a nature that the solution is channeled from the plates to a circuit that dispenses the solution to an accumulation chamber. Such plates are considered to be fully gasketed, and are the type often used in refining. The picture posted by 4metals is of such a plate, and while the plates, below, vary somewhat, they function the same way. 

I had suggested I would post some pictures of a filter press I built for use in filtering cyanide solutions from my agitation tank, but they had to be copied from a photo album first. I found time to accomplish the task when my modem died, leaving me without access to the forum for several days. Hope you find this interesting

The press pictured is closed by the ten ton hydraulic cylinder, a necessity to overcome the pressure developed by the slurry pump. Because the amount of travel of the cylinder is minimal, and the press is closed only infrequently, the press is equipped with a hand pump, capable of producing 10,000 psi hydraulic pressure. Slurry is introduced to the press via the large center opening of the plates, which align with the center of the head plate, where the press manifold is located. The four corner O rings form the channels that carry the solution from the press. There are channels under the filter media that cover each plate, directing the filtered solution to the ports, and, in turn, from the press, where they are stored the large black barrel nearest the press. The large O ring seen on each face serves a dual purpose, one of which is to secure the filter medium, with the other to seal the plates when under pressure from the hydraulic cylinder. 

This press was built to filter cyanide solutions from an agitation tank. While they are similar in construction, the plates were machined from polypropylene, with stainless hardware. 

The slurry pump is a diaphragm pump that is air driven. Such pumps will operate until they stall, with no damage to the pump. The two black containers function as a storage system for both the slurry and the filtered solution. They were plumbed such that each could function as the supply for the pump, so the initial discharge, which may not be free of flocculence, can be recycled until the discharge is clean. Filtering with a press is much the same as filtering by funnel, whereby the initial discharge may not be clean, but it slowly improves as the filter media gets covered with solids, quickly yielding a crystal clear solution. 

The press was provided with a manifold system that permitted blowing down with compressed air, so the press could be fully emptied of solution. 

Harold

edit: corrected spelling


----------



## leavemealone (May 23, 2009)

Hey Harold,hows the house coming?Thats what I want to see pics of(dont forget to add pics of where you keep your gold...lol).Hey that last pic looks like one of the electrowinning cells I was going to make.Even though its not I don't think it would be too hard to convert it.....hint hint.lol.Ok well gotta run,have a good weekend.
Johnny


----------



## 4metals (May 23, 2009)

Harold,

You are a master craftsman, a beautiful press!


----------



## Harold_V (May 23, 2009)

4metals said:


> Harold,
> 
> You are a master craftsman, a beautiful press!


Thanks for the kind words. 

I have a background in the aero-space industry, so I am, forever, cursed with a streak of perfectionism. I take great pride in doing a job well. 

If you have not reviewed my personal page, I worked as a machinist/toolmaker. Building equipment wasn't an issue for me. 

For the record, the filter press functioned perfectly. 

Harold


----------



## Harold_V (May 23, 2009)

leavemealone said:


> Hey Harold,hows the house coming?Thats what I want to see pics of


Coming along nicely, albeit slowly, Johnny. I'm finishing the drywall right now, a decision I do not regret. Doing so has been very revealing in ways you may not understand. 

I'll try to take a picture of the front in the near future. Just an average home, but with a large room for the stereo system.

Thanks for asking. I appreciate your interest. 

Harold


----------



## leavemealone (May 23, 2009)

> a large room for the stereo system


 :shock: :shock: :shock: :shock: 
SWEEEEEET!


----------



## qst42know (May 23, 2009)

Awesome filter press Harold. All without the use of a CNC, even more so. Identical pieces are where CNC equipment excels but to make this on manual machinery really shows off your skills. Very cool indeed.


----------



## Harold_V (May 24, 2009)

qst42know said:


> All without the use of a CNC, even more so. Identical pieces are where CNC equipment excels but to make this on manual machinery really shows off your skills.


Thanks, but it's not really that big of a deal for anyone that has worked as a (pre CNC) machinist. For me, just another day in the shop. When I broke into the commercial shop ('57), there were no methods for duplication aside from cam driven screw machines and hydraulic duplicators, which required a template. Even NC's were not on the scene yet. I was trained in light production, so it's not a hard task for me to make identical items (per print) in quantity. 

The plates for the press were quite involved. There are four buttons arranged @ 90° intervals on both sides of all of the center plates, and on the inside of the front and back plates, which help transfer pressure to the end plates, avoiding collapse of the thin center sections, which form the cavities. It took a great deal of thought to come up with a functional combination, plus I had to allow for the thickness of the filter medium, so when the press was closed there was sufficient contact to lend the necessary support without destroying the filter material. 

Harold


----------



## semi-lucid (May 24, 2009)

So Harold, you've shown us your leaching vat, and now the filter press, how about the ball mill?  

Nice looking press, the steel plates look like their blanchard (sp) ground?

J


----------



## Harold_V (May 25, 2009)

semi-lucid said:


> So Harold, you've shown us your leaching vat, and now the filter press, how about the ball mill?


I've posted a picture before, but I'll post it again, below. 



> Nice looking press, the steel plates look like their blanchard (sp) ground?



Correct. They had to be flat in order for the plates to seal. My shop wasn't equipped with a Blanchard, but I had a friend that ran a grinding shop. Subbed the job to him. 

Harold


----------



## 4metals (May 25, 2009)

Harold,

Your ball mill is a work of art as well! Continuous feed, I thought you only worked small lots? Wise choice though if you only have 1 mill a small to medium capacity with a continuous feed can handle small lots and large lots.


----------



## Harold_V (May 26, 2009)

4metals said:


> Harold,
> 
> Your ball mill is a work of art as well!


  

Thanks! I was pleasantly surprised at the results I achieved. I'd never been around a ball mill, but after doing some research, I came up with a design. It was simple, but very effective. Built to go the distance, too. The shell was 3/8" thick, with a charge of balls that ranged from 2" down to about 3/4", plus a generous sampling of some large rollers from bearings. 



> Continuous feed, I thought you only worked small lots?


Excellent observation! 

I did work in small lots, but I also had need to monitor what was happening, so having a continuous feed/discharge allowed me considerable control over the end results. I could easily control the output by regulating the water flow, so I could run the material long enough to achieve the desired results. Very little got cycled a second time, perhaps 5% at best. I used a fine screen at the end of the chute to classify the discharge, with larger pieces held captive in the ball mill by a restricted dishcharge. Nothing larger than 1/8" could leave the ball mill. 

I knew that I would run the resulting material in the agitation tank, with cyanide, so I had to control the pH so it would be safe to introduce the cyanide. I added lime to the operation, checking pH continually. My target pH was just under 12. When the affluent pH started drifting lower, I'd add lime. Being continuous feed made it easy. 

My original idea was to gather a percentage of the gold by amalgamation. There was a considerable amount of visible gold, although a great deal of it was visible only under magnification. The chute was lined with copper. Sadly, I discovered that the gold would not amalgamate. I had removed various pieces, which were placed in a vessel of mercury. They floated, refusing to wet. That gave me a clue that the free gold was light in weight-----leading me to conclude that it was a gold telluride. Don't know, to this day, if I was right, but the decisions I made turned out to be proper for the ore. I achieved over 99½% extraction of the gold, but only about 50% extraction of the silver. 

The ore in question assayed over 300 oz/ton, but I had only (4) 5 gallon buckets of the material. I have posted a picture of some of the pieces that escaped processing, a gift to me by the rightful owner of the ore. 

For the guy that had never studied chemistry, and was a miserable student in school, I was very pleased with the outcome. 

Harold


----------



## nicknitro (May 26, 2009)

Harold, 

I saw my niece this weekend, she is 7, and she was talking about school and how "know-a-days" her class was seperated into groups. Like math for example, kids that were very good at multiplication were put into one group , addition, subtracion, division, the like. I thought this very strange. She was very self-concious about not being very good in one of the groups, and I felt this sounded like lunacy, so I gave her my best advice ever.

I told her, "It's not how smart you are to begin a subject, but how hard you work, at learning how it works that makes the difference." 

I went through school taking all those apptitude tests, and being told that I was above average, so I took it easy quite a bit. Well those few final years, they really took it's toll on my grades. No scholarship, no funds from family, it is tough to work and pay for schooling as well.

I got off on the Wahhh Wahh's, LOL, My point being, Harold, You earned your education through hardwork, and experience. For that, you should be very proud. Many people venture off into self-employment everyday and more file for bankruptcy, everyday. Living your life, and gaining the knowledge you have, I think you should profess somewhere, if you were willing.

P.S. I talked to my VP the other day about manufacturing an Induction Brazeing system the other day, "I guess I shouldn't have shown him the examples from other companies." , as he just wants to buy a system. I was looking forward to the break from the everyday blahh.

Thanks, 
Nick


----------



## Harold_V (May 26, 2009)

nicknitro said:


> I went through school taking all those apptitude tests, and being told that I was above average, so I took it easy quite a bit.


When I was in the 5th grade, I was tested. My teacher felt I was unable to learn. The results shocked everyone. I was found to be performing @ 9th grade level. All my life I have been disinterested in many things, which I totally ignore. Politics is one of them. In spite of a feeble attempt, I can't get interested. School was that way for me, until I could choose the subject matter. I did very well in classes that held my interest. Slept through the others, especially history. Even slept through English---so to this day I don't understand why I'm able to put two words together. 



> Well those few final years, they really took it's toll on my grades. No scholarship, no funds from family, it is tough to work and pay for schooling as well.


There is usually a price attached to indifference. Because I didn't pursue an education, I faced many obstacles in my quest to succeed in my chosen field. Luckily, with the help of one incredible human being, I was saved from my own stupidity and learned my trade well (machinist). 

I encourage you to continue your education, in spite of the hardships involved. An education will not guarantee success, but it will make the task easier, and you'll be far better suited to the position in life you may find yourself. 



> I got off on the Wahhh Wahh's, LOL,


A noble and valuable service has been provided by you. It may help those that are on the fence to make the proper decision about extended education. 



> My point being, Harold, You earned your education through hardwork, and experience. For that, you should be very proud. Many people venture off into self-employment everyday and more file for bankruptcy, everyday. Living your life, and gaining the knowledge you have, I think you should profess somewhere, if you were willing.


Thanks for the very kind remarks. While I appreciate your thoughts, I don't feel I'm qualified to instruct. In keeping with my typical performance in life, I have learned that which satisfies my curiosity, but there are many instances where I don't have a clue------such as being able to explain chemical reactions. The best I can offer, and it often shows in my posts, is to do it the way I say to do it. I know it works, often very well, but I am at a loss to be able to explain why. It doesn't take too much of that to lose the trust of those that you are trying to instruct. 

A closing note. Success in one's quests requires a few things. One of them is to have reasonable expectations. A good example of that might be to not be the one to try to dispel the notion that there is no perpetual motion. All of the reasons that it can't be are well known and published. Why spend a lifetime on something that will fail?

Success is a state of mind. If you are well grounded and have reasonable goals, they can be achieved. 

I founded two businesses in my many years. Both of them were resounding successes. One of them was my machine shop, the other my refining service. In both cases, they were simple operations, but I chose to be the best at the work involved. My attitude was (and is) that no one could do it better. Being totally reliable and trustworthy was also important to me. My work had to stand above that of others, otherwise I was not pleased. I firmly believe it was key to my success. 



> P.S. I talked to my VP the other day about manufacturing an Induction Brazeing system the other day, "I guess I shouldn't have shown him the examples from other companies." , as he just wants to buy a system. I was looking forward to the break from the everyday blahh.


In this case, that's probably a sound decision. If you've been around any induction heating equipment, you likely understand the complexity of the problem. You could spin your wheels endlessly trying to create the right combination of features, but then I have no idea of your abilities, do I? :lol: 

Harold


----------

